THE LONDON: FRIDAY, DECEMBER 23, 1870. THE difference go to? The train was stopped at drivers ever disregard block signals also ?— the signal box to tell the driver to shunt, and this is a point that railway managers and then in the action of the train starting might investigate a little. We may now MECHANICS' MAGAZINE. again the coupling was broken; that, accord- come to Wembley, and we find that the ing to the driver, the train was re-coupled at signalman there declares that in compliance 5.21. Did a space of nine minutes elapse with signal from Harrow, he blocked the line between the stoppage to instruct the driver for down trains; he also states that he was and the repair of the coupling? If so, then much surprised at the driver of the express the Harrow officials are the responsible passing it without notice, so much so indeed, parties for the collision, supposing that the that he went out up the line some forty yards THE HARROW COLLISION. times of the two trains were strictly observed, to try if the lamp were burning properly and HE inquest on the late collision at Har- but we find this is not the case, for another saw the red light distinctly. He does not row has terminated and the verdict been witness states that the express is always found mention much fog, and the two facts, first recorded. We have waited for this before five minutes late, and leads us to suppose that he did examine his signal to see it was making any remarks on the affair, but now this unpunctuality is in some degree relied on in order, and, secondly, that he did see it propose doing so, and in order to place the to help out the time allowed for shunting forty yards off, as well as his saying that matter clearly before our readers will first goods' trains, and that if the goods' train was the fog was not great, goes to exonerate shortly recapitulate the circumstances. An seven minutes late, being really due at 5.5, him from blame for not putting down fog empty goods train left Willesden at 4.55 on that the express never passed Harrow till signals. Now we come to another item. We the afternoon of Saturday, the 26th of No- 5.22. Indeed, the driver of the trailing or know both from personal observation and vember last, and reached Harrow Station on second engine to the express train states they from evidence at the inquest that sometimes the North-Western Railway at, according to did not, he thinks, reach Harrow till 5.24; hand-lamp signals are given to drivers, to more than one witness, 5.12. This train and thus it appears that there actually was save trouble in working the heavy main ought to have shunted into a siding in time ten minutes space or more between the signal up and down again in one operation. to leave the main line clear for the Man- arrival of the two trains; but we have already The driver of the trailing engine dechester express, which left Euston at 5.0, seen that according to the evidence nine of poses that, owing to the steam, &c., and which was due at Harrow at 5.17. The these precious minutes elapsed between the from the pilot engine, he could not see goods train was stopped by signal at the arrival of the goods at Harrow and the the main signal, but that he did see a white signal-box for orders, and when being started amending of the breakage. The driver, lamp in the signal box. This is an imporagain, the coupling between the seventh and however, states that if all were right the tant statement. In fact, if we take and comthe eighth waggons from the engine parted. train could be shunted in two minutes; yet bine the acknowledged laxity of drivers at Before this could be re-coupled, the Man- here are nine lost in stopping the train to times about "caution" signals, the practice of chester express ran into the goods train, and instruct the driver (which we must include hand-lamp signalling, with the presence of the an engine and some carriages in the express in the two minutes equally, as it was evi- white lamp in the window, we have pretty were smashed to pieces, while several pas- dently the regular practice to stop the train well arrived at the conclusion that the driver sengers were killed on the spot, and many more at the box) and in repairing the coupling; of the pilot engine, knowing in the first were injured more or less seriously. That is therefore when the coupling broke, the place that Wembley was a long distance from the brief statement of the disaster itself. train moved forward, backed again, and was Harrow, and, secondly, that, as we are told, The steps taken to avert it were, that the again coupled, during which nine minutes the block was always up at Wembley, he did signal, "line blocked," was telegraphed at had elapsed. Surely under the existing pres- not pay the special attention he should once to Wembley, distant about two miles, sure for time it need not have taken so long, have done to the signals there, and seeing and the signal was acknowledged; further- because logical reasoning tells us that if two the white lamp, he held on his course. Here, more, as the evening was foggy, a man was minutes suffice to move a whole train for- then, we have a third cause for the accident, despatched up the line with fog signals, but wards a given distance and then back it into or to sum them all up-first, we find that from the evidence given by one witness, some a siding, the same time ought to suffice to nine minutes time were wasted or lost at five or six minutes elapsed between the move a part of the train forward and back it Harrow; secondly, that owing to the same breakdown of the coupling and the despatch on the same metals again. defective organisation of the working staff at of the messenger. We may now proceed to Harrow which caused the loss of these nine a little analysis of the evidence, and, first, in so minutes, time was also lost in sending fog far as it bears on the primary question of signals up the line; while, thirdly, from lax the time allowed by the company's rules discipline about the observance of signals, between the arrival of the two trains, we the express passed Wembley without pulling find as follows:-William Crowshaw deposed up. All the three lead us to think that, however that he was an enginedriver in the service of elaborate are the rules to protect passengers the company, and drove the engine of the from injury, something yet remains to be train of empties, into which the express subdone to increase their chances of safety. We sequently ran. He left Willesden at 4.55 would, in consideration of the circumstances with instructions to shunt for the five o'clock of this Harrow affair, suggest that railway express train. There was a train timed to managers should make it a rule that no leave Willesden at the time he started, and truck or vehicle of any kind should be secured to shunt at Harrow for the express; witness with a single coupling, and to ensure that was running in the time of that train. Did not double or triple couplings are used, a special notice what time they arrived at Harrow, but We must next refer to the fogging busi- officer in every case should be held responsible after the waggons had been coupled he looked ness. The rules of the company appear to that they were so fastened. As trucks are at at his watch and found the time to be 5.21. make the driver and guard responsible for present connected, they each have a hook and Before reaching Harrow he was stopped by this in the event of any breakdown between a chain at the centre of each end beam; both signal at Wembley cutting. Did not notice stations, but within station limits the station- chains ought to be put on to the opposite the signal till he was quite under it because master is responsible. Here in this case, hooks. Furthermore, we consider that, owing it was foggy Now it is well known that however, we find that from defective organi- to the fatigue of the couplings from pergoods trains, however punctually they may sation of the working staff at the station, petual jerks, and the consequent crystalstart to time, never afterwards mairtain that some four or five minutes elapsed from the lisation caused in the metal, independent punctuality. We cannot, from the evidence breakage before a man could be found to go side couplings should be applied, similar to before us, find that there is a special observ- up the line to lay fog signals. There is little those used on passenger carriages. We would ance of time, either by rule or by practice, for doubt that, had there been a man present recommend springs being likewise fitted in the goods train in question; we are told whose special business it was to attend to all cases to the centre coupling or draw bars. that this train is started by signal from the fogging under the circumstances, the sig-This should be done by fitting a number of city box, and we find the driver stating that nals would have been sent far enough to india-rubber disc blocks on the shanks of the his instructions were to shunt at Harrow in have stopped the express in time. Here, drawbars, and caused to bear against the time for the express. What meaning is then, we find a second cause for this collision. beams. This would save much of the injury attached to the expression "in time"? We It may be said that the line being blocked to the bars from jerk action in starting. find from the rules of the company that ten at Wembley that was thought sufficient, and minutes is the minimum time allowed between therefore less pains were taken about "fogthe arrival of a train to shunt and a follow-ging"; but if perfect confidence were reposed ing fast train. We find in the present case, in the Wembley block, why send any fog however, that this time was not adhered to in signals at all? We must attribute their a legitimate manner. Indeed, the evidence being sent as arising either from anxiety to on this is a little conflicting, as we find that two or three witnesses say the goods arrived at about 5.12, but the driver states that when the coupling was repaired he found the time to be 5.21. Now where did this nine minutes The conclusion we would draw from the foregoing is, that as the goods' porters at stations are supposed to assist at shunting, they ought to be drilled to take each a certain duty, and one man ought certainly to keep near the middle of the length of the train, so as to be in a position to communicate signals between the driver and the rear of the train. A string of fifty, or even forty goods' trucks is a long one, and in the dark fog of a December evening the driver is almost entirely ignorant of what occurs at the rear of a train. Had the driver known sooner of the breakage the collision might never have happened. make assurance doubly sure, or else that In respect to the officials and their duties at stations, we think that the existing discipline or organisation is imperfect; every man and boy should have certain definite duties assigned them, and be held responsible for their proper execution. The verdict of the jury has been to the effect of a four-fold censure, inasmuch as it states that the driver of the pilot engine neglected the signals at Wembley, that the signal man at Wembley was to blame in not different colours, but generally exhibiting a greenish hue, and white when decomposed. Organic remains are of rare occurrence in this formation, and it is only lately and in the neighbourhood of Bendigo that distinct specimens of graphtolite have been found. This widely spread palæozoic series of rocks, the waste and refuse of the primitive cooling crust of the earth's surface, was deposited, slowly, gradually, and without interruption in horizontal beds, which thus obtained the thickness they now present. laying fog signals, that the company's rules the future inhabitants of the earth, invest that were not complied with, and that the work-substance the king of metals-with a ing hours for the signal-men are excessive. peculiar and exciting interest. Its royal Such a verdict was perhaps as good a one designation, originally conferred upon it by as could be expected from a coroner's jury, the alchemists, no doubt was suggested in but we confess that it appears to us rather an consideration of its precious physical and illogical one. We can hardly see how the chemical proporties. These are comprised Wembley man and the driver can both be in principally in its extreme density, indestrucblame, for if the former was neglectful in not tibility, resistance of oxidising influences, its putting down signals, how could the driver amazing malleability and durability, its beaube in fault to neglect that which was not tiful colour, and the almost incomparable there to attract his attention? Again, how lustre it may be made to assume. The incan the signal-man be to blame, if the jury numerable purposes to which it is applied, While, however, there are no apparent considered him unable for his duties from and its wondrously attractive nature when signs of mechanical disturbance during the over work. put into the form of current coin of the realm, long period that must have elapsed from the need only to be glanced at here. The multi- cooling of the earth's surface to the deposifarious forms of beauty it is made to take tion of the Silurian and Cambrian systems when modelled and fashioned by art are it is to be presumed that the internal igneous universally known and acknowledged, and, in activity of the earth's crust was in full force, short, the sway of the king of metals is un- so that on the inner side of it, in obedience bounded by territorial limits and unrivalled to the law of specific gravity, chemical by that of any other earthly potentate. attraction, and centrifugal force, a great Now, although the paramount influence segregation of silica in a molten state took and magical power of gold are everywhere place. This molten silica continually accuadmitted, and its characteristics as a metal mulating, spreading, and pressing against are generally known, the story of its birth, the horizontal Cambro-Silurian beds at and its genealogy, so to speak, are com-length forced its way through the superinparatively mysteries. Those parts of the globe cumbent strata in all directions. It is abunin which it has been generated and cradled dantly clear that under the conditions of this most extensively are supposed to have been force and the resistance offered to its action almost wholly explored, but of the actual the line it would, and indeed must, choose process of its formation in the earth's crust- would be a continuous and slightly inclined its creation-but little information has diagonal one, at times crossing the strata of hitherto been given, even by the most dis- schist, but preferring to develop itself and tinguished geologists. It is our good fortune find egress between the planes and dividing to be in a position to contribute something seams of the different schistic beds. towards the accumulation of a stock of knowledge on this recondite and occult, but most deeply interesting subject, and to make "the great stone book" itself yield testimony as to the origin of gold. That the company's rules were not complied with is scarcely the fact, because they were fulfilled, but not in an efficient manner, the inefficiency arising from a defective station discipline, that we must suppose to be habitual. We most cordially endorse the statement of the jury, that they thought signalmen overworked. We consider that nine hours out of the twenty-four is amply sufficient time for them to be on duty, and we also consider their wages of 19s. a week quite too little for the class of men required for such responsible duties. Another matter likewise demands attention, and that is, what we must call the cumbrous method at present in use for working the semaphores. It is regular hard labour to manipulate their levers, and we cannot see why the working of a signal should be made ten times as laborious as to handle a pair of 800-horse power engines. With reference to the practice of merely securing single coupling on trucks, we presume this is done to economise time, but we must protest against such an excuse being advanced, and so long as no special provision is made by railroad companies to secure double and independent couplings, we consider the companies responsible for disasters such as that at Harrow. We are convinced that many persons escape death from similar catastrophes by a hair's breadth; of course, no one knows of these narrow escapes but the officials. If nine minutes were wasted out of the ten allowed for shunting on the day of the collision, is it not only too probable that similar waste takes place at other times? To the exertions and observations of a practical engineer who spent many years in Australia, and who may be said literally to have dug up his facts and to have examined them by the light of science, we are indebted for what will be found to be far more than mere speculations as to the creation of the "king of metals." From his note-book we are privileged to cull extracts and to make deductions, and sure we are that both will be deemed interesting in the highest degree by the readers of the MECHANICS' We would in conclusion recommend a more MAGAZINE. Our intelligent instructor in the enlarged application of the registering system first instance gives some account of the geoloof trains, signals, times of shunting, &c.gical features and the cadastral peculiarities Above all, we would call for a strict record of the gold regions of Australia, and then of the actual number of minutes elapsing advances at once to the question of the creabetween the removal of one train into a tion or origin of the precious metal. siding, and the passing of a succeeding one at that point, and more than that, a copy of this particular register should be transmitted to a Government inspector every month. We do not hold with those who suggest an increased number of mechanical arrangements for signalling. We have yet to be convinced that existing arrangements are insufficient if they are really worked with efficiency, and this efficiency can only be attained by taking care to secure the best men; to do which, a more liberal scale of salaries should be paid than there now is. Men should have full command of their energies, both of mind and body, if they are to have charge of our lives, and these energies they will certainly not have if they are overworked. And added to these changes a more perfect organisation of our railway staff should be put in operation. Thus were formed in a more or less horizontal position and in all directions innumerable flakes and extensive sheets of quartz rocks, apparently interstratifications as regards their "strikes," but not really so, for they distinctly traverse and intersect the underlay of the slate rocks, and being thicker between the schistic rocks and narrower where intersecting them. From the quartz rocks started quartz veins, some running almost parallel with it and others perpendicular to its position, whilst others, again, shot out in capricious planes and directions. These veins or "leaders" all ran out to comparatively short distances, and especially so such veins as cut across the slate at the planes of greatest resistance. Simultaneously with the upheaval of the granitic rocks of the Cambro-Silurian slates in average meridional line the approximately horizontal main quartz belts were upheaved and placed on edge along with the schist strata. It is in consequence of this diversity that the quartz belts are apparently interstratified, whilst in reality they are merely intersected. Thus horizontal sheets of quartz reefs which had been forced between the schistic cleavages and different strata appeared as almost perpendicular quartz lodes, their strikes being conformable to the general meridional bearing of the schist and the coincident line of upheaval and their underlay intersecting that of the slate to the east or west. He remarks that the auriferous quartz lodes never continue their course into the granite, that they are, on the contrary, invariably broken off as it were at the point of contact, that they are twisted and turned from their due course, or else broken up into fragments, that the quartz lodes are intersected by granite dykes, that fragments of granite are never found in quartz lodes, and that in some instances these last have been subjected to the metamorphic action of granite. These facts, when viewed sequently The veins which ran parallel followed the and logically, prove to demonstration that main course of the quartz rock, the perpenthe quartz lodes are of a date anterior to the dicular veins becoming horizontal or flat, eruption of the granite rocks. There are while the others took their respective analoquartz lodes nevertheless sitting in granite, gous positions. In the same manner the and which are said, on doubtful authority, to horizontal sheets of quartz rock when upbe auriferous. Should this latter position be heaved in the medial line of action would established, it would certainly argue in favour show along their approximate meridional line of the more recent formation of quartz lodes. a varying shoot to the north or south. In At present there is no good reason for anti-quartz lodes when there is no noticeable or cipating that that position can be maintained. well defined shoot in either direction it may The admission that the quartz lodes are of be inferred that their original development carlier date than the granite induces was indifferently either north, south, east, or THE prominent and important part which naturally to an investigation of the subject west, and this is precisely the appearanc gold has played in the history of mankind to a far more remote period of the earth's which auriferous quartz lodes present in from the utterance of the first syllable of history, and when the Cambro-Silurian beds nature to the miner and the geologist. They recorded time to the present hour, the enor- were still undisturbed in their original hori- form innumerable and more or less perpenmous influence it now exercises upon the pur-zontal position. The Cambro-Silurian system dicular quartz dykes, and extensive quartz suits and the character of civilised and un- of the country presents a series of coarse and rock belts, which strike with very few excep civilised humanity, and its probably almost of fine grained sandstone containing few tions on an approximate meridional line, unlimited power, for both good and evil, over marks of slaty structure, slaty sandstone of thus disclosing to view, on a gigantic seale, THE CREATION OF GOLD. an that remarkable parallelism which after all is but a natural feature consequent on the almost unvarying strike above alluded to. These auriferous quartz lodes intersect the strata of the slate rocks, and are cased with walls of slate and sandstone. They have quartz veins issuing from them in various directions across the country as leaders, flat veins, &c. Sometimes they form themselves into irregular masses of veins, at other times they appear as massive bodies of quartz rock, which dwindle into mere strings connecting with other rocks of a like character. may be put forward it is fairly presumable or piers. The economy of this plan of conthat it holds out tolerably good prospects of veyance is very questionable. Once on the eventuating a remunerative undertaking. farm the sewage is distributed by gravitation, We are not speaking now of people taking but in the first instance it has to be pumped up patents and inventions of their own, in to a certain height in order to command the which they have the strongest possible land. The lift is small, not exceeding 27ft. interest, and are naturally inclined to regard The pumps are worked by a horizontal highthe future in the most sanguine light. The pressure engine of 8-horse power, and the case to which we allude is one in which a steam stands at about 50lb. pressure. Both company or a private individual, having engines and boilers are in duplicate, so that good grounds to believe in the soundness should any accident happen to one set, the and commercial validity of an enterprise, is other can be immediately had recourse to. willing to invest capital in it. It is scarcely As yet it appears that there has been no These indisputable facts go to prove that possible to imagine a better test than this of necessity for resorting to this alternative. the quartz lodes, when forcing their egress, the soundness of any project, and it may be Nevertheless the precaution, which some may often disturbed, fissured, and rent asunder stated that if a proposed undertaking in- consider as entailing an unnecessary degree the enclosing schists, the openings so effected volving considerable expense and the of expense, is unquestionably a wise one. It being instantly filled by the quartz stone, and ordinary justifiable amount of risk will not must be borne in mind that the sewage must thus giving rise to those capricious, irregular, or stand this ordeal it is not sound at the core. be pumped up into the reservoirs; it cannot zig-zag shapes vulgarly termed "east and This is the test that is now being applied to be permitted to remain in the conduction west veins." But there are other than the the principle of the utilisation of sewage by pipes. It is always being produced, and cosmic and geological conditions mentioned irrigation. At present the scale upon which must as incessantly be disposed of. This is which prevailed at the time of the formation the application has been effected is very one of the obstacles to be overcome in the of the quartz lodes, and they also indicate the limited, but with success will unquestionably removal of town sewage and its application Plutonic character of this dyke formation. come a great improvement in this respect. to land. Once the system is commenced it Under this head is to be reckoned the occur- It is true that it is some years ago since the must be continued without the slightest inrence of felspar in quartz veins, for it is an principle was first actually put into practice, termission. Directly the sewage is delivered established scientific truth that mica, felspar, but it is only very recently that it has been on the farm the future disposal of it rests and amphibole or angite, are all minerals regarded as likely to prove remunerative to with Mr. Hope. which cannot be formed apart from igneous capitalists. Until the present the data upon chemical action. This single circumstance which to form even an approximative estialone goes far to prove the original molten mate of the financial results have been too state of the silica of quartz lodes. Another meagre and uncertain to be considered argument to the same end may be drawn reliable. It was not until the produce per from the fact that the auriferous quartz lodes acre of the different grass, cereal, and root have exercised a manifest metamorphic action crops assumed a definite annual character on the adjacent walls or casing. They have that their respective values could be arrived done so partly in a mineralogical sense, but at. Spasmodic yields, although unprecegenerally there will be found a true meta- dented in quantity and quality, do not afford morphic alteration of the rock. that guarantee, that solid assurance, which is furnished by a steady continuous return. "breccie Yet another proof of the igneous origin of the original quartz lodes consists in the me- Prominent among the few who have chanical disturbance caused by their protru- interested themselves seriously in the subject sion. It is constantly observed that the of the utilisation of sewage by irrigation is strata of the schistic rock are more or less Mr. Hope. From the first that gentleman contorted, that their underlay is variable to has perceived the immense importance of the east or west, that fragments of them are the whole question, as bearing upon the entangled in and metamorphosed by the sanitary welfare of the nation and the requartz lodes, and that in consequence the fertilisation of the soil. Being satisfied with adjacent country is, to use a mining expres the results of his experience, acquired at the sion, broken up into fragments forming a Lodge Farm, Barking, and elsewhere, Mr. of commingled slate and sand- Hope a short time back made arrangements stone, whilst the quartz lodes traverse the with the local authorities of Romford to same country intact and unbroken. From take the sewage of the town and utilise it on the foregoing evidences it can be safely the irrigation principle upon a farm situated maintained that the gangue of the auriferous some few miles distant. It is needless to say quartz lodes is of igneous origin, and not the that the offer was accepted, and the requisite result of a gradual deposition of quartz from arrangements entered into between the cona silicious solution. Into the negative de-tracting parties. In all probability the ductions supporting the above incontestable Romford Local Board was exceedingly glad statements as to the origin of gold which to transfer the responsibility that rested with might be adduced it is not essential to enter. them of disposing in some manner or another A second and concluding paper will enable us of the town sewage to so able and expeto deal with the metalliferous peculiarities of rienced an agent as Mr. Hope. The authoriquartz lodes and other phenomena relative to ties were thus at once relieved of all trouble the creation of gold. and anxiety respecting the obtaining of the land, the preparation of the plans, negotiation with the Local Government Act Office, THE ROMFORD SEWAGE FARM. and a host of similar preliminary operations, F all countries England owes most to the which they were both unaccustomed to and individual enterprise of her sons. The unacquainted with. In a word, they found possession of our great Oriental dependence it to be more to the interests of the ratewas the result of the energy and persever-payers to place the disposal of the sewage at ance of a small body of men who had the the command of Mr. Hope than to undertake sagacity to appreciate and the strength of the utilisation of it themselves. The nature purpose to effect a settlement in a distant of the mutual agreement and conditions may land. In this respect alone we form a strong be summed up briefly by observing that the contrast to other nations. The majority of Local Board undertook to deliver the sewage the extensive works of construction which on the farm, receiving an annual payment have been executed by Continental countries from Mr. Hope in return. In order to have been designed and carried out under adequately effect the utilisation of the the patronage and with the assistance of the sewage there was consequently a certain respective governments. At home the con- amount of work to be carried out by the trary is the rule; it is true that government Board as well as by the lessee, which may does execute many important works, but be noticed separately. The farm upon which even in those instances where it assumes the the sewage is utilised is about four miles surveillance it delegates to private con- from Romford, and the liquid is conveyed tractors the duty of actually constructing to the locality in cast-iron pipes, which for the work. When it is found, therefore, that the greater part of the distance are laid persons otherwise disinterested are willing underground, but at intervals are carried to place their capital in any project that above the surface upon small brick supports One of the first points of difference that strikes a person who is familiar with the physical features of a sewage farm, as existing between the one in question and others, is that there are no surface main carriers. They are all raised to different heights above the level of the ground, and are formed of semicircular troughs of sheet iron carried upon wooden trestles of the simplest description. Some of these carriers near the pumping station are from 12ft. to 15ft. in height. It is by no means accurately ascertained what is the most economical description of carrier to employ. A distinction must be made between the main carriers alluded to and those which are of much smaller dimensions, and must in every case be formed in the ground itself. At Barking, Croydon, and elsewhere, the system of carrier in vogue at Romford has never been tried, but a very short time ago the surface or ground carriers at the Lodge Farm were being gradually filled up and obliterated, and it is intended to carry the supplying channels above the ground. The relative economy of the two methods will depend a good deal upon the physical contours of the land. The adoption of wooden or iron carriers saves all formation of the ground channels, except those of a secondary character already mentioned, and to some extent they obviate the objections urged against surface channels in consequence of their giving off during very hot weather an unpleasant effluvium. It is frequently more economical to carry a line of railway upon a series of arches than to construct a solid embankment for it, and it is not difficult to perceive that by analogous reasoning it may be, in certain instances, cheaper to carry the line of carriers in a sewage farm over the ground than upon it. experience, however, is necessary before this question can be conclusively settled, especially if the works are intended to be of a permanent character. In that case it is probable it would be well to slightly increase the thickness of the sheet iron troughs, so as to allow for contingent corrosion, and also to construct the trestles or supports in a more durable manner. The iron carriers at Romford are 15in. by 12in., in lengths of 7ft. 6in., cold-riveted at the joints, and further tied together by light iron straps passing across. They cost about 7s. per yard run. It wil be admitted by all those who have seen the farm we are describing that these carriers do not present a very sightly appearance. A more economical description, and one which has a more pleasing effect, can be constructed of concrete, and a few hundred feet or so in length of this kind have been laid out for the purpose. Further tionable, but it must be remembered that Cyclopædia," the ledgering is recommended; The population of Romford numbers about ten thousand, and the number of acres of the farm taken by Mr. Hope amounts to 120 acres, thus giving something less than the ordinary allowance of a hundred persons to the acre. The accurate proportion in this respect is affected by other considerations than the mere ratio of population to acreage, but taking the extremes it may be said to range from 50 to 150 persons to the acre. The dilution of the sewage, the proportion of the rich to the poor in a town, and many other local circumstances will very materially modify the calculation that is to be made on this point. It will take some years yet before we arrive at a correct estimate of the actual ratio that ought to be observed in this case. It must manifestly depend in some measure upon the crop that is to be raised. It obviously cannot be right to apportion the sewage of a certain proportion of the population of a town to an acre irrespective of the nature of the produce of that acre. If grass be the crop planted it is well known that a far greater number of tons of sewage can be allotted to it than if the ground were planted with a cereal or root crop. Not only is the quantity varied according to the crop grown, but the times and intervals at which the sewage can be applied are also dependent on the same cause. At Romford the farm is laid out altogether on one principle, namely, It follows from the foregoing statistical the pane and gutter, and in this respect it and other reliable information, that for the differs from others in which the different public convenience at home and abroad systems are embodied. The natural features there exists at this moment in the shape of of the ground must in every case determine coined British money-gold, silver, and that particular system upon which it is best to lay out the land. This condition will also be slightly altered according to the character of the crop to be grown. A plan of formation that would be highly advantageous to grass crops would be exceedingly detrimental to cereals and roots. In every instance the natural lie of the land must be consulted. The Romford farm constitutes the first case of its kind, and we hope it is prophetic of what is to follow. The Barking farm may be quoted as an analogous example, but it great difference between the Barking and other farms which are established for dis posing of town sewage. At the Lodge Farm, Barking, the sewage can be taken at any time it is wanted, and need not be taken if bronze-nearly 700 millions of pieces. The NOTICES OF BOOKS. Tshould be called "ledgered logarithms." the searcher to turn to his letter at once. "The Young Mechanic "* is a capital book for boys. It contains a large amount of easy and cleverly defined lessons on carpentry, joinery, tin and ironwork, soldering, &c., and other subjects of a similar character, starting at the beginning, such as cutting a piece of wood with a knife (a boy's first plaything), up to the practical use of gouges, chisels, and other tools for lathes and machinery, such as are in use by adult mechanics, thus rising step by step from simple experiments to more extensive ones. The author has rendered good service to boys by producing this book, and we hope his reward will be shown by them in purchasing one each, or asking their parents to do so for good bold type and on good paper. them as a Christmas present or a new year's gift. The book is well illustrated, printed book for boys, or it is supposed to be one, Cassell's "Technical Educator" is another must be borne in mind that there is this ledgering of the index of a ledger, enables but we cannot praise its contents. In the And the tables of logarithms and anti-almost as many subjects, and these are sixty-four pages it contains, it treats upon ledger. But another new feature presented The subjects selected are not at all suitable for logarithms are separate, each having its crammed into the smallest possible space. by this table is that it gives every five the young, and it is surely those who require figures with their five figures of logarithm or of antilogarithm so that there is no inter- teaching. Some of the articles are so learned in their character that none but professors polation whatever. And, though not very would take the least interest in them. The important, the fifth figure is always correct. For instance, we want the logarithm articles on technical drawing are far from figures for 18463. In the common table, we tract one passage as an example, from page what we consider they should be. We exdo dictionary until we have found 1846, and we find 26623 with a tabular difference of not required. At Romford and elsewhere it must be taken and provided for at all times, and in all weathers wet and dry. LAST YEAR'S COINAGE AT THE 66 24. Our fifth figure is 3, and by a small Again, suppose we had wanted the primitive ROM an official return just published, we FROM enabled to gather and summarise for the public information the quantity of coin of each kind struck at her Majesty's Mint during the year 1869. There is something fascinating about the subject of money, and even statistics become interesting when they deal with "hard cash." The return before us is almost entirely made up of figures, but still its contents, rightly regarded, are by no means dry reading." They are indeed eloquent witnesses to the commercial of leaves or calculation of proportional parts. We have then logarithms without turning activity of the country, and they demonstrate But where is the use? Can we not whip off a the fact-perhaps pretty well known before logarithm quite as quickly in the common -that there is a brisk demand for money way? No doubt, if logarithms were never among the Queen's lieges. To commence, wanted more than one at a time, we might as then, with that queen of coins, the sovereign. well mount a siege-gun to shoot a solitary Between the 1st of January and the 31st of franc-tireur as set Mr. Scott's table going December, 1869, the Mint yielded in exchange But when a job of calculation requires scores for bank nuggets, 6,444,322 of those hand-or hundreds of logarithms, the saving will be some specimens of its manufacture. Of half- very perceptible with practice. The use of the sovereigns, 1,864,764 were minted during the table may be entirely managed with the left same period. These make a total of new hand, so that the pen need never be out of gold coins for the year equal in nominal the right hand. This is something. value to £7,375,694 sterling-a sensible addi tion to the one hundred and odd millions of English gold coins previously in circulation. The augmentation of the silver currency of Great Britain in the same year was propor In the article "Tables" of the "English "Tables of Logarithms and Antilogarithms to Five 11: "The T-square is to be worked against the left-hand edge of the drawing-board, and should be used for horizontal lines only; perpendiculars are best drawn by working the if the 1-square be used for perpendicular set-square against the T-square, for as well as horizontal lines, the slightest inacwould prevent the lines being at right angles curacy in the truth of the edges of the board to each other." Why should not care be taken to make the it is more solid to work from a board than two edges at right angles to one another to prevent" the slightest inaccuracy?" Certainly from a set for vertical lines; the set has only about 24in. to 3in. base, while the T-square has at least 10in. or 12in. The first part of the paragraph says that "the T-square is to be worked against the left-hand edge of the board:" the sketch shows it as working from the right-hand side. Messrs. Partridge and Cooper, Fleet-street, have issued a very nice office almanac. "Whitaker's Shilling Almanac for 1871 "‡ CASSELL, PETTER, and GALPIN, Ludgate Hill. The Young Mechanic," a book for boys, containing directions for the use of all kinds of tools, price 3s. 6d. TRUBNER and Co., Paternoster-row. Whitaker's Almanac for 1871." By J. WHITAKER Warwick-lane, Paternoster-row, is something more than its title indicates. It should have been "Book of Information with Almanac." The vast amount of particulars set forth in its 300 and odd pages is beyond degcription. The particulars are in a condensed form, but sufficiently explicit for the purpose. We are unable to identify one page of greater value than another; whether it relates to naval, military, commercial, scientific, statistic, or any other matter, each subject is dealt with with due regard to the interests associated with it. The usual weather and date chart is, of course, given besides the calendars for high water, Church lessons, and astronomical notes. YESTERDAY'S ECLIPSE OF THE SUN. complete the ample information we have Tgiven about the preparations to observe the INSTRUCTIONS FOR THE SPECTROSCOPIC OBSERVATION NOTE.-The objects to be obtained are:- in 9. Record the impressions of facts, and facts not adapted for a general survey, not requiring any already noted, as soon as possible. INSTRUCTIONS FOR THE POLARISCOPIC OBSERVA TIONS OF THE CORONA, INCLUDING BEAMS AND STREAMERS. limitation of field; the double-image prism is better adapted for a comparison of the oppositely them directly, not one with his memory of the polarised images, since the observer can compare other. The double-image prism will require a amination of the corona be carried on as follows:It is recommended that the polariscopic ex-diaphragm with a long and moderately broad aperture in the focus of the eye-piece, rotating 1. To examine a detached and selected part of with the prism, and in the observation the length the corona about 6 from the limb of the sun, and should be placed in a radial direction. (say) about 8' in diameter. 2. A field extending from the limb of the sun outwards should be examined either with a Nicol's prism or a double image prism. THIRD OBSERVATION.-The observation of the streamers as to polarisation might throw much light on their nature, and the observer who undertakes this observation, by means of a Savart's polariscope, or else of a Nicol's prism capped with a plate of calc spar or arragonite, will be in a condition to determine with advantage the plane of 4. The polarisation of the corona should be ex-polarisation, if there be polarisation, of the corona amined in such a manner as to eliminate atmo- generally. But the streamers must be his first spheric polarisation. object. 3. The light of the streamers at some distance from the sun should be examined with a Nicol and a crystal. NOTE.-The most suitable instruments for as FOURTH OBSERVATION.-It has been supposed certaining the plane of polarisation and the pro- by some that the polarisation observed in the (3). A plate of quartz consisting of two wedges turned through an angle of 180deg. (4). A plate of arragonite, or cale spar, cut perpendicular to an optic axis, and affixed to an analysing prism. (5). A polarimeter consisting of four plates of glass, movable on an axis perpendicular to the plane of polarisation. GENERAL REMARKS. corona was really due to the secondary illumination of the intervening portion of the earth's atmosphere, in other words, to the illumination produced by reflection from clouds, &c., towards the horizon. This effect may be eliminated by using a Savart's polariscope, or, better, a polariscope with quartz wedges, and turning the instrument till the bands (if any) seen on the moon's disc disappear. The corona can then be scrutinised as to polarisation, and the polarisation examined in different azimuths of the Nicol's prism FIRST OBSERVATION.-The object of this obser-relative to the radius drawn from the sun's centre, vation is to observe the polarisation (if any) of the by pointing the telescope instead of rotating the corona without having the observer's attention analyser. In this observation the observer has distracted by the chromosphere. A Savart's the choice of two rectangular azimuths of the polariscope is recommended by preference. polariscope, for each of which the bands (if any) The Nicol's prism of the polariscope should on the moon disappear, and if no bands be seen on be set beforehand with its principal plane (or the moon he is free to scrutinise the polarisation plane of symmetry) radial, .e., perpendicular of the corona by turning the polariscope. to the sun's limb, and the observer must note whether bands are visible, and if so, whether they are black-centred or white-centred. Should the bands be feeble it will be well to rotate the polariscope, prism and plates of course moving together, and quickly restore it to its primitive azimuth, after having noted the estimated azimuth of the Nicol when the bands are strongest and black-centred. Should no bands or only dilute bands be seen it may be that the corona, though polarised, is overpowered by other light; and the observer will move the telescope from the sun, radially if it may be, if in any other direction, rotating the polariscope so as to render its principal plane radial in the new position. He will then note whether, though the light becomes feebler, the bands become less dilute. Should, on the other hand, the bands be strong, after having satisfied himself as to the plane of polarisation, the observer will endeavour to make out whether by means of the polarisation of its light the corona can be detected superposed on the chromosphere. The observations should be conducted as ful- He will therefore move the telescope towards the lows: 2. To determine if there exists cooler hydrogen above and around the vividly incandescent layers and prominences. To do this the band of the spectrum just above the stratum, which gives the H lines before totality and during totality, should be carefully examined, to notice (a) if any traces of the H spectrum exist above the region which before totality gave the H lines, and (b) what lines extend outside the H spectrum, and whether they also exist with it in the lower strata. 3. To test the American observations of last year as to the existence of a line at 1474 in the corona spectrum by seeing if it be visible above the region which gives the H spectrum. 4. To determine whether any other gases or vapours are ordinarily mixed up with H, but remain invisible with the uneclipsed sun in consequence of the absence of saliently brilliant lines in their spectra. 1. Work with a horizontal slit, or a slit in a parallel declination, according to the instrument used, whether altazimuth or equatorial. 2. See that the spectroscope telescopo works easily, so that sweeping along the spectrum is easy. 3. Find before totality an average plain-topped region of the chromosphere, where some motion on either side does not brighten, or thicken, or lengthen the lines near the part covered at the commencement of totality. 4. Observe this before and during part of totality, the telescope being driven by the clock if an equatorial is used. 5. Just before totality sweep from red to violet, note the lines and their length, mark the 1474 line and the lines between D and E carefully. sun, keeping the principal plane of the polariscope SECOND OBSERVATION.-The special object of this observation is to differentiate, if possible, between the corona, on the one hand, and the chromosphere, or whatever else may be self-luminous (be it even a portion of the corona itself), on the other. This will be possible if the light of the corona be strongly polarised, so as to admit of comparative extinction by an analyser. The 6. Immediately after the commencement of observer should turn the analyser so as to extotality sweep back; note new lines their tinguish, as far as may be, the light of the heights, especially the comparative heights of C, corona in the neighbourhood of a radius dependnear D, F, and near G, with these former heights; ing on the angular position of the analyser. He and especially whether band over b and the should notice the form, colour, and general apthickness of F. Note also the lines between Dpearance of any residual luminosity other than the well-known protuberances, should contrast the appearance, especially as to colour, with that seen when the light is analysed so as to retain light from the same region polarised in the perpendicular direction, and should ask himself whether the luminosity is such as could be accounted for by the superior brightness near the sun of the unanalysed light, even though it were to suffer the same proportionate loss by analysis as the corona at a greater distance. Of the instruments named, the Nicol's prism is better and 1474. 7. Just before the end of totality unclamp and bring back the slit to the following limb of the moon, and note the extinction of the spectrum by the reappearance of the sun, if possible, by a rapid sweep; if this is not possible then watch the behaviour of F; sweep back again to see if there be any variations from (5) in the new region now observed. 8. Carefully note position angle where slit cuts limb. The object glasses of all telescopes intended to be used in polariscopic observations should be examined before their departure as to their freedom from defects of annealing. Double All polariscopes, including a Nicol's prism, or taurmaline, should be marked, so that the principal plane may be readily known by feeling, as sight-marks might fail for want of light image prisms should have one side of the aperture in the diaphragm marked so as to distinguish the two images. INSTRUCTIONS FOR THE SPECTROSCOPIC OBSERVATION OF THE CORONA. NOTE. The word corona is here used for convenience, to include all the light above the prominences. It therefore includes that part of the chromosphere which is generally veiled to us when observations are made by the JanssenLockyer method. The principal object to be obtained is: To determine whether it is possible to differentiate the outer layers of irregular outline and streamers from a stratum, say, some 5 or 6' high around the sun, which may possibly be the limit of the gaseous envelopes above the photosphere. To attack this question, we require a long slit, a large aperture, and long collimator, and small dispersive power. The slit must be adjusted for a faint cloud before totality, and on no account is it to be touched before observations of a similar cloud can be made after totality, by the heads of the party. The most important observation to make is, whether there are any dark lines in the spectrum at any distance from the sun; and if so, at what distance? Next, whether there are any bright lines; if any, their positions must be noted, especially the lines recorded by the American observers are again visible. The observations should be conducted as follows: 1. Arrange the instrument so that the image of the following limb of the moon, at the point of its first contact, will fall on the left-hand side of the slit, placed nearly horizontally. 2. See if corona is visible before totality, and note its spectrum with utmost care, moving the slit in azimuth, so that perhaps, at the instant during totality, while possibly with a long slit, the spectrum of the sun or prominences on the preceding limb is visible in the same field of view. |