THE WHITWORTH GUN IN FRANCE.

There are

They have constructed at the Seraing works 1,687 steam engines of from 4 to 600-horse power for industrial applications, 675 locomotives of all sizes and systems, and 11,650 machines forming complete works and parts of works, for raising and reducing coal and minerals, the working of metals, for construction, sugar factories, the making of ice, paper making, weaving, bridges, suspension bridges, &c.

Tho works of Sir John Cockerill and Co. can furnish annually 50 locomotives of the first class, 70 marine engines of from 4 to 1,000-horse power, 1,500 lots of mechanical constructions, 3,000,000 kilogrammes of bridges and like structures, 14 ships and boats, taking 5,000 tons of material besides coal, coke, minerals, castings, wrought iron, rails, and steel in the quantities before mentioned. Every department is kept strictly apart, proprietor.-" Mining Journal.”

a noble front for the works, which are situated on that of St. Petersburg 14 hectares, and their own the banks of the Meuse. This company carry out mines 11 hectares. Independently of the above A DOCUMENT has come into our hands which in the whole operations, from the raising of the coal they hold under Government for getting coal 195 directly throws considerable light upon the and minerals to the turning out of the finest en-hectares, and for getting mine 3,500 hectares. present condition of the field artillery of the French gines, bridges, iron-clad ships, &c. The general army. It will be remembered that Sir Joseph director is M. Sadoine. The area covered by the Whitworth sent to the last Paris Exhibition two works is 90 hectares, one-eighth of which is specimens of his steel field-pieces, the one a 10-entirely taken up by buildings. The number of pounder and the other a 3-pounder. These guns, persons employed in 1867 was 7,227. They pay having attracted the notice of the Emperor, were annually for salaries 6,660,000 francs, and employ sent by his desire in the first instance to Ver- 156 steam-engines, of the collective nominal sailles, and afterwards to the camp at Chalons, for horse-power of 2,843. The yearly amount of work exhaustive experiment, under the direction of the constructed is valued at 25,000,000 francs, and Commission Permanente d'Experiences, and it is the quantity of fuel consumed is computed at The yards of Antwerp and St. Petersburg have their report which we have now before us, dated 220,000,000 kilogrammes. The collieries employ fnrnished for navigation 174 ships, river boats, so recently as last year. It is a most valuable 2,175 persons, and steam-engines of 628-horse pilot boats, floating lights, dredgers, transports, document as a record of the performance of Eng- power. There are four separate places of extrac-packets, floating docks for frigates of the largest lish field guns in the French camp, but its chief tion, and eight pits or shafts used for raising the size, and iron-plated monitors. The two armourinterest at the present moment lies in the un- coal, ventilation, and the descent and ascent of plated monitors with tower, propellers, and madoubted evidence which it affords of the great in- the work people by means of the fahrkunst, or chines for towers, ventilators, gun carriages, feriority of the field guns, made of bronze, with man-engines. From these pits are raised centrifugal pumps and accessories, supplied to which the French artillery is equipped in the war 260,00 0,000 kilogrammes of coal. They employ Russia in 1864, having been ordered on June 18, with Prussia, at least as compared with English 195 men and women to convert coal into coke, 1863, were sent for finishing to St. Petersburg in steel guns. This evidence is supplied by a series and steam-engines of 87-horse power. There October, 1863, and booked to the Imperial authoof tables near the end of the report, in which the are five lots of coke ovens (of two classes), six rities, fully equipped and armed, after trial, on performances of these latter guns are compared stamps or pounders, two washing machines, and June 13, 1864, having been commenced and comwith those of the "canon de quatre de campagne," eight steam drying furnaces, for preparing the pleted ready for service in less than twelve as regards range, lowness of trajectory, retention coal before it goes to the ovens; 80,000,000 kilo- months. of velocity at long distances, and accuracy. In all grammes of coke are produced annually. these particulars the French bronze gun was much inferior to both of the steel guns, and in some steam-engines of 224-horse power. In the mines are employed 875 operatives, and respects is so inferior as to bear no reasonable thirty places where the mines are extracted, in comparison with them. Even at 5deg. of eleva- the provinces of Liege, Namur, and Luxembourg, tion, the range of the 3-pounder exceeds that of and the total amount produced yearly is the French 10-pounder by 290 metres, while the 146,000,000 kilogrammes. There are five blastEnglish 10-pounder exceeds the other by 440 furnaces, with steam-engines of 548-horse power, metres. But as the range increases the inferiority and employing 288 persons. The blast-engines of the French becomes much more marked. Thus, are very powerful, and produce a pressure of blast so that each one seems to belong to a separate at 10deg. the French gun ranges 2,350 metres, the equal to 34lb. to the square inch. The boilers English 3-pounder 3,120, and the English 10- and hot-air furnaces are heated by the waste pounder 3,320. At 20deg. the ranges are 3,480, gases. The annual produce of iron amounts to 5,000, and 5,490 metres respectively; and at 30 50,000,000 kilogrammes. In the foundries 256 deg., while the range of the French gun is but work people are engaged, and the engines are of 4,100 metres, the English 3-pounder has a range 32-horse power. There are eight cupolas, and of 6,100, and the 10-pounder 6,890 metres. These 360,000 kilogrammes of moulding boxes. They inferior ranges of the French gun are associated, have two separate buildings for core making and as they must be, with correspondingly high flights drying; 5,000,000 kilogrammes is the weight of or trajectories, rendering the aim of the artillery-castings turned out annually. In the iron works man very uncertain in the field, where distances that is, the mills and forges-985 operatives have to be judged hastily and by the eye alone. are engaged. The steam-engines are of 532In ranging 2,000 metres the French shell rose to horse power. There are 68 reverberatory a height of 83 metres, while the highest point of furnaces, 13 rolling mills, and 5 hammers. the trajectory of the 3-pounder was 54 metres, and Plates and sheets, merchant iron, and specialities of the 10-pounder only 51 metres. At 3,000 are produced yearly to the total weight of yards' range the maximum ordinate of the trajec- 10,000,000 kilogrammes, and rails to the amount tory of the last-named gun was 130 metres, that of 25,000,000 kilogrammes, making in all of the 3-pounder 137, and that of the French gun 35,000,000 kilogrammes. The steel works employ 253 metres! Those who understand the relation 191 work people, and steam-engines of 520-horse between a low trajectory and good aim in the field power. There are 2 large Bessemer converters, will discern the immense disadvantage of the 5 ordinary furnaces, 24 casting furnaces, 15 French gun in this comparison. Not less remark- reverberatory furnaces, 7 hammers of from able is its want of conservation de la vitesse, or the to 15 tons, 1 rolling mill of very large quality of keeping up the power to hit hard dimensions, and 2 rolling mills for railway throughout its flight. The initial velocities of the wheel tyres, fitted with all necessary hydraulic projectiles of all three guns were nearly alike, apparatus. The annual production amounts to varying between 331 and 361 metres per second; 7,500,000 kilogrammes of wrought and cast steel, but after travelling 1,000 yards the velocity of the steel rails, tyres in steel and iron, and steel castFrench projectile fell to 247 metres, that of the ings for machinery. steel 3-pounder being still 302, and that of the 10pounder 311 metres. At 2,000 yards the velocities

As the pene

were 194, 276, and 282 metres; and at 3,000
yards 166, 252, and 264 metres.
trating effect of a shell depends upon its velocity,
it is easy to see how inferior the French arm must
be in this respect likewise. Its inferior accuracy
is also very remarkable, especially at long ranges,
but we have not space to record all the figures.
Those already given are taken without alteration
from the official report. It is only necessary to
add that bronze is of less than half the strength of

good steel, or of Whitworth metal, and that much
of the inferiority of the French gun is attributable
to its use, it being quite impossible to fire the full
charges of powder and length of projectile from a
bronze gun of given bore without speedily destroy-
ing it." Times."

A MODEL IRON WORKS.
THE WORKS OF SIR JOHN COCKERILL AND CO.,
BELGIUM.

AMERICAN WONDERS.

has been alleged that excellent butter may be from the fetid stuff which remains in such a great extracted from Thames mud, probably also mass at the bottom of the Serpentine. Some peras to the allegation being a fact. Why should sons are nauseated by the idea, others are sceptical they? as great alimentary wonders occur in other parts of the world. The "Territorial Enterprise," Nevada, gives an account of a curious hot spring about one mile from Eiko on the old White Pine road, a great natural curiosity-a spring "the like of which is perhaps nowhere else to be found in the whole world. seasoned with pepper and salt, cannot be disThe water, when properly tinguished from the best chicken soup. Of the hundreds who have partaken of it all agree that it has precisely the taste of chicken soup or broth." Three pounds of beef boiled in the water of the spring yields as much soup as could be obtained from twelve pounds of meat cooked in common water. It is, happily, a spring "of considerable size," and one of a group. It is "at the top of a little mound of loam and sediment." Just so! Does this not justify, to some extent, the Thames mud butter theory? The water is admirably In the iron forges, engine and machine shops adapted, the Enterprise further informs its there are 1,184 persons employed, and engines of readers, for hatching chickens, and several large There are 23 reverberatory batches have already been hatched by the profurnaces, 13 steam hammers, 230 lathes, 18 slot-prietors, who find the operation inexpensive. The ting machines, 84 planing machines, 90 drilling veracious reporter states that chickens are hatched machines, 5 machines for forging nuts and bolts, with little trouble and at no expense at steamboat and 3 hydraulic presses. The quantity of engines springs in the same locality. "There is hot water and machines constructed annually amounts in and steam enough there," he states, "to hatch weight to 7,000,000 kilogrammes. The boiler and out ten acres of eggs in one batch." And he bridge yards employ 573 persons, and engines of demands elegantly and with wonderment, "Why 35 punching machines, 7 sets of rollers for bend- utilise all this waste hatching power?" There are 18 drilling machines, don't a chicken-hatching company be formed to Echo ing plates, and 20 shearing, planing, multiple may well answer "why?" drilling, and riveting machines; 4,000,000 kilo- the paper that contains this remarkable statement grammes of steam boilers, bridges, &c., are made we find another, that "the war between Prussia

224-horse power.

42-horse power.

annually. In the Antwerp shipbuilding yard 319 persons are engaged. There is one steam engine of 8-horse power, special docks for all classes of marine constructions, shipbuilding sheds of glass, rafts and boats, machines for masting, stocks, and launching cradles, both for sea-going vessels and river boats. The weight of marine constructions made yearly amounts to 2,000,000 kilogrammes. From 75 to 800 operatives are employed in the St. Petersburg yard, and it is furnished in every reThe annual a small machine shop in a very small way; but productions weigh 1,500,000 kilogrammes. There the works have gradually grown till they now are 111 managers and clerks belonging to the occupy the whole of the extensive gardens of the establishment. The area of the works is divided ancient bishops of Liege, the present offices in the following maLner:-The Seraing works having been the fine old palace, so that it makes cover 72 hectares, the Antwerp yard 5 hectares,

JOHN COCKERELLing, in 1917. He started in spect similarly to the Antwerp one

OHN COCKERILL, an Englishman, established

In another part of

and France has proved a severe blow to trade in petroleum," Germany furnishing the best market, and the oil having been chiefly carried in German ships, now, of course, withdrawn. May it not be said of this chicken-soup_water that a greater than petroleum is there? Twelve pounds of beef at (say) 9d. 9s., three pounds only to pay for 1s. 3d., no less than 6s. 9d. discount in 9s.! Should not this leave margin enough for freight, and a handsome remuneration to the proprietors who have "struck oil " of such a wonderful kind? Why not ship chicken-soup water instead of crude petroleum?

Another American wonder, of a less pleasing character, merits reference. It is a ball-throwing machine in process of construction on the east

side of New York Bay. This machine is to be

BY MR. A. FREEMAN.

capable of throwing eight hundred five-ounce balls APPARATUS FOR MOVING RAILWAY CARRIAGES a distance of two miles in a minute. The gun, if we may call it so, is not very intelligibly deINTO STATIONS AND SIDINGS. scribed thus in a New York paper:-"This gun is circular in shape and looks like two discs of iron plate, some four feet in diameter. On one side is a funnel, which conveys the balls through to the proper chamber without cessation of firing or diminution of speed. The muzzle projects upon the periphery of the circular machine and can be elevated or depressed at pleasure by the trunnion on which it rotates. The machine is so constructed that it may be worked either by manual labour or steam power, and when worked by the latter it will throw shot or shell up to the weight of eight pounds, while only slightly diminishing the number thrown. In either case the shot may be red-hot or cold." If what is predicted of the capabilities of this new infernal machine prove true, the contrivers will be entitled to front rank places among the engineers who apply their talents to that branch of the profession that may be called the science of destruction.

THE TRAVELLER'S TRANSIT
THEODOLITE.

THE theodolite shown in the annexed engraving

sional astronomical observations. The object in designing it has been to condense into the least possible bulk the smallest instrument with which useful results can be obtained. Its telescope gives it the advantage of optical power, and it has complete 3in. circles, both horizontal and vertical, with verniers showing to one minute; it can, therefore, be used not only as a theodolite for terrestrial surveying, but also as an altazimuth for determining time, latitude, and azimuth astronomically. It

will be found convenient in use, its diagonal eyepiece admitting of zenith stars being observed with perfect facility. It is supplied with a reflector for illuminating the wires at night, with a dark glass for solar observations, with a finely divided level, a compass, and with the means of performing all the adjustments necessary in such instruments. It packs in a mahogany case, 4in. by 5in., and 63in. long (outside measure), the whole weighing only 34lb., a light tripod staff is also added.

The theodolite is manufactured by Mr. L. Casella, of Hatton Garden, London, who is the maker of such instruments to the Admiralty, the Ordnance, the Indian, American, and Russian Governments.

THE "TARAPAGA" FAIRLIE ENGINE

A built on the Fairlie principle, was tried at
VERY powerful and large locomotive engine,

Peru, on which some steep inclines have to be got
over; some of them, we understand, are as sharp
as 1 in 11 for a long distance. The total weight
of the engine is 60 tons, and is calculated to draw
an enormous load. One of the novelties in this
system is that there are two foot plates, one for
the driver and one for the stoker, the fire-box
being between them, as before mentioned; the
water tank is on the foot plate near the driver,
and the coal bunker on the stoker's side. The
engine was severely tested at the trial on a line of
almost circular form, one portion of it being only
of 50ft. radius.

on the shoulder taking into holes provided for them to hold it in place. The lever has a prop pinned to it, the lower end of which is forked to embrace the top of the rail, so that when the lever is in position a downward pressure on its free end forces the carriage along. A foothold is secured for the brace by means of a steel fork, which, as the lever is depressed, clamps upon the rail and cannot slip. Now it will be seen that the lever may be worked up and down with a rapidity increasing as the inertia of the car is overcome, and the fork or shoe will take a new and advanced position on the rail at each elevation of the lever. The power obtained by this combination of the THE BRITISH HOSPITAL FOR DISEASES knee joint and lever is sufficient applied with the strength of one man to start and move a loaded car under almost any circumstances. The link which may be seen lying on the lever

OF THE SKIN.

A. RIVINGTON, the hon. sec. of the

Mabove institution, informs us that a bank can be thrown forward into the position shown by

The apparatus has been suggested by Mr. A. Freeman, of Fairbury, Illinois, U.S.A.

note for £1,000 has been sent anonymously to the dotted lines, and hooked on to the spur, when
him, and that the committee of management have a slight motion of the lever will draw the spur and
devoted this addition to their resources to the detach the jack from the car.
purchase of the lease of their premises in Great
Marlborough-street, and to the establishment of
an in-patient department, which is much needed
for the proper treatment of the severer cases of
disease that are daily applying for relief. But the
sum so generously placed at the disposal of the
committee, large as it is, falls far below what is
necessary for the maintenance of the in-patients
whom they will shortly be ready to receive. They
hope, however, by the aid of further contributions,
to be enabled to atilise in the manner proposed
the munificent gift that has been entrusted to
them. For those who may desire to aid so meri-
torious a work we may state that contributions of
one shilling and upwards in stamps, or by post-
office order or cheques, forwarded to the secretary
at No. 56, Great Marlborough-street, will be thank-
fully acknowledged.

APPARATUS FOR MOVING RAILWAY
CARRIAGES INTO STATIONS AND
SIDINGS.

EV

11

the Hatcham Ironworks, near New Cross, on
Thursday and Friday, the 11th and 12th inst.
The engine is the largest ever built; it was
mounted on twelve wheels, in two sets of six at
each end, and with the fire-box in the middle; VERYONE has noticed the absurd way of
each set was coupled and driven direct from cy- "making up a train in our large stations
linders fitted to the bogies, the steam being car- by the employment of a number of men pushing
ried down to the cylinders by flexible jointed pipe. and pulling the carriages along. We say absurd,
The engine is what is called double-ended, that is, because a little thought on the part of the engineer
it has a boiler leading from the fire-box towards or of the directors would produce a mechanical
each end, the boiler being simply placed upon contrivance by which a carriage loaded or empty
saddles to enable each bogie to turn and follow could be moved with ease by one man or by two
the curve of any part of the line with freedom. men at most. Our American friends are more
Steam can be taken to work the cylinders at alive to the wants of the age than we are, at least
either end, or at both ends, according to the load so it seems, from the simple contrivance illustrated
to be drawn or the incline to be mounted. The above. It consists of a lever to be attached tem-
Tarapaga is constructed for one of the lines in porarily to the carriage or waggon by the spikes

ON THE PRESERVATION OF TIMBER. THE THE subject of our present paper is one that has occupied a leading position among the scientific questions of the day at any time within the memory of the present generation. Since the commencement of the present century it has been the subject of no less than 45 patents, and there are some on record in the last century. We believe that, with some unimportant exceptions, these are now all expired, and any detail of their specialities is of course beyond our limits, and would also be useless. We only propose to refer to them as we have to describe the various processes which have been adopted with more or less success with a view of preserving timber from what?-from wet rot, from dry rot, from the attacks of land and marine insects (of which we shall take as types the white ant, of tropical climates, and the Teredo Navalis, the "Paal Worm" of the Dutch), and lastly from fire.

Wet rot and dry rot are often confused with one another, and we briefly distinguish them thus:

Wet rot is the rotting of unseasoned timber, by what we may call the fermentation and subsequent putrefaction of its own sap, of which the most noted and disastrous instance of modern times were the gunboats made for the Crimea. Dry rot is a similar result produced by causes external to the timber itself, a humid atmosphere and want of ventilation being, however, almost always if not invariably attendant causes.

In tropical climates, notably in India, the white

ant will devour the interior of massive timber beams, leaving a mere shell on the exterior, until collapse tells the tale of the mischief that is done and it is well known that in the seventeenth century, Holland, that country reclaimed from the sea, and which to this day owes its existence to the durability of its dykes, was seriously threatened with inundation by the destruction of the timber of which they were constructed by the "Paal Worm."

Such are the foes we have to encounter, and we propose to give a short account of the methods that have been adopted with more or less success in the attempt to defeat them. The earliest attempt on record at the "Preservation of Timber" was made when Noah built the Ark, and "pitched it within and without with pitch." And, strange as it may appear when our remarks are concluded, it will be seen that the material then employed, or a cognate one, is the leading commercial article of the present day for the same purpose.

described, mostly, if not entirely, out of date, now
occupies an important position among the com-
mercial undertakings of the day. It consists in
impregnating the timber with creosote, or heavy
oil of tar, and upon this subject we shall go into
considerably more detail.

most effectual method. We now propose to give a detailed description of the most extensive establishment of the day in which works for the preservation of timber from decay are being carried on, and to add some remarks on the general commercial position of the question at the present time, with notes of some of the most successful instances of its application.

Having thus briefly sketched the evils to be guarded against in the preservation of timber, and the various processes adopted for their pre- Referring to the various processes already vention, we will proceed to a few remarks upon described above, we now propose to give a the durability of different descriptions of timber, short synopsis of what is now doing, remarkunder different circumstances, giving instances of ing that the creosoting process far exceeds success and failure. The piles of Old London all the others in extent and importance. With a Bridge were of elm, and after being driven into view of ascertaining how the work was done, and the ground under water for 800 years those that what facilities existed for the adoption of various were removed in the course of erection of the processes, we paid a personal visit to the premises new bridge were as sound as when they were first of Messrs. Burt, Boulton, and Haywood, adjoining driven. Elm was used for water pipes during the the commercial docks, an extensive wharf, coverlast century to a considerable extent, and its ing four acres of ground. The same firm have power of resisting decay in damp earth is the also a similar establishment at the Victoria Docks reason of its universal use for coffin boards. On of five acres in extent, the two together forming To return to modern times, the earliest patent the contrary, when elm is exposed alternately to the largest timber-preserving, or, as the phrase on record was taken out by Alexander Emerson wet and dry it decays rapidly. The unfortunate goes, pickling establishment in the world, and we in 1787; the ingredients were boiled oil and some gunboats before alluded to were in part con- will briefly describe what we saw. The late Mr. chemical compounds, and it was simply applied structed of elm, as under the war pressure the Burt was probably the greatest authority upon in a heated state to the outside of the timber. authorities had given permission to use elm instead the subject, and for some of the detail given John Lewis, in 1754, prepared a kind of varnish of oak in planks, and as after a few months' use above we are indebted to a paper by him, from plantation tar, which he used in the same the gunboats were drawn up on the slips, the tim-read before the Institution of Civil Engineers, in Humphry Jackson, in 1768, patented a ber was placed exactly in the position where its 1853, on the "Nature and Properties of Timber." process for boiling the wood in a solution of chalky rapid decay was a matter of certainty. As the We were accompanied by the present head of the matter, or a preparation of vitriol. In the early most powerful contrast to the above example of firm, Mr. Boulton, to whom we are indebted for attempts, mostly designed for shipbuilding pur- decay we may quote many instances in mummy very complete information. poses, we find the first suggestions of the subse-cases and other works executed by the ancient quent processes which have successively contended for their share of public support.

way.

In the first quarter of the present century many more patents, based more or less upon the same principles, were taken out, until in 1832 we meet with an entire novelty. "Kyan" took out a patent for preserving timber and other materials by soaking them in a solution of corrosive subli mate or chloride of mercury. There are various instances, as, indeed, there exist of many of these processes, of complete success, but the difficulties were great; the material, as is well known, is a dangerous poison, and so insidious in its effects that the men employed in the work become subject to salivation, or the result of mercurial poisoning, and thus a practical difficulty arose.

Egyptians more than 3,000 years ago; which,
though the record of the actual process is, of
course, lost, present all the appearance of the best
method of creosoting as executed at the present
day.

Another objection was its cost; it was too expensive to be used efficiently at a paying price for the market, the trade was subsequently transferred to a company, and got into disrepute, and commercially we may say that kyanising is no more. In 1837, Mr. Margary enrolled a patent for the preservation of various materials by soaking them in a solution of sulphate of copper-the blue It has been ascertained that wood grown in vitriol of commerce. This had an undoubted suc- situations where fungi abounded is more subject cess, and, though the patent is expired, is occa- to dry rot than other kinds; and we may sionally employed at the present time, especially here remark that in the docks we have often abroad, in certain situations to which we shall noticed timber stacked so as much to facilitate further allude. The objection to this, and to all the development of the germs of decay, which the other processes where the timber is impreg-it has evidently contained when unloaded from nated with a soluble salt, is that under the changes of atmospheric temperature, especially if the work is alternately wet and dry, as in tide, the work gradually absorbs moisture from the atmosphere, and in process of time the efficacy of the preservation disappears.

Sir W. Burnett's patent is dated 1838, and he impregnates the wood with a solution of chloride of zinc, which he states forms an insoluble compound with the albumen of the wood. This process was to some extent used for government works, and where it can be kept always dry, it undoubtedly hardens the wood and protects it from the attacks of insects; it has also the effect of rendering it almost incombustible, but in practice during a course of years, it has been found that it is subject gradually to atmospheric influences, and its efficiency is materially impaired by lapse of time if it is exposed to weather. As to the method of application of these solutions, so that they may thoroughly permeate the wood, or sufficiently so for protective purposes, we propose to give full detail in the sequel.

In 1841 Payn's principle was patented. It consists of using two solutions in succession, which act upon each other with the object of forming an insoluble substance in the pores of the wood, e.g., sulphate of iron and carbonate of soda will form oxide of iron in the pores of the wood. Various modifications of this process are still sometimes used, but there is no firm in existence for the purpose of carrying them out. We may almost say the Paynising, the same as Kyanising, is, commercially speaking, a thing of the past.

We now come to another process, patented by Mr. Bethell in 1838, which, unlike those already

The failure of many of the earlier processes doubtless arose from the fact that they relied for the saturation of the timber, with whatever material they employed, upon simple soaking; the great variety in the density of various qualities of timber, and even the difference between different pieces of the same kind, rendering the result uncertain; while, unless by actually weighing the timber after the process had been completed, there was no satisfactory means of ascertaining what quantity of solution was absorbed by each piece. Boiling was sometimes resorted to, but with a somewhat similar result.

The question of dry rot is one so familiar to all of us that we do not propose to quote any example, except that both in seasoned and unseasoned timber it arises from various species of growth of a fungoid character, which decompose and reduce to powder not only the sap but the organic tissue of the wood itself, and there is this peculiarity about it that the germs of the fungi in a building Many years of experience have led to the adopthat is once infected appear to be carried out as tion of the principle of injection in a vacuum it were in the air, and that it is not necessary that under pressure, which we shall now describe. In actual contact should take place between the the establishment in question there are four large whole and the infected portion for the spread of cylinders, 6ft. diameter, of various lengths up to whatever we may term the disease, whereas in the 80ft., in which the timber is pitched. They are wet rot actual contact between the decaying or of the same construction as an ordinary steam putrifying portions and sound wood seems neces-boiler, and the timber is run into them on rails, on sary. So that we may describe dry rot as infec- which travel small trucks or trolleys upon which tious and contagious, while wet rot is only conta- the timber is piled. When the cylinder is charged, gious. it is closed by a spherical shifting end, which swings round upon an arm, and completely closes it with an air-tight joint, and is secured in its position by shifting iron clips round its entire circumference. The cylinder being charged and closed, the next process is the exhaustion by an air pump, worked by a 20-horse power engine; and, for the information of those similarly engaged, we may state that the cylinder is considered ready at the point indicated by 20deg. of the Bourdon vacuum gauge. When this point is reached, the creosote, which is contained in tanks adjoining, is admitted at a temperature of about 120deg. Fah., and, as a natural result of atmospheric pressure, it rushes in and fills the cylinder to within about two inches of the top. Pressure is then applied by forco pumps, worked by the steam engine, and in degrees varying with the nature of the goods and the quantity of creosote required to be injected-about 150lb. per square inch sufficing to force into the body of the timber a quantity (by measurement) of creosote, equal to from forty to sixty gallons, according to quality. The time required for the process varies from the weather and other causes, but may be taken at a fair average of eight hours. Every stage of the proceeding being regulated by steam and vacuum gauge, the actual results are ascertained with the greatest nicety.

the ship.

With regard to the worm there are various species, some of which prey upon wet timber and some upon dry. One called the Lymexylon does serious damage in oak stacked in large quantities in the north of Europe. There are other species of minor importance with the detail of which we need not trouble our readers.

Of marine insects the Teredo Navalis, and called by French engineers the Taret, is an inmate of many of our harbours. Portsmouth, and other ports round the south, Great Grimsby, Lowestoft, and other places without end can tell their tale of the destruction and expense occasioned by its ravages, in some instances piles of 14 square being eaten away to 4in., and in some cases totally destroyed. The insect next in importance is the Limnonia Terebrans especially found in southern climates, but its habits are not so well known, the same opportunities of observation not having occurred, as has been the case in regarded to the Teredo.

The demand is extensive for railway sleepers Having thus given a short account of the various especially, and is not confined in its application to causes of decay, and an historical sketch of the this country; a very large business is done in different processes adopted for preservation, we France, and several of the principal railway commay further remark that in ordinary house-build-panies are now employing the process, and works ing the dry rot is one principal enemy, while the have been carried out, or are in progress, for offensive smell of creosote renders it inapplicable Holland, Prussia, Spain, Turkey, South America, for internal use. We must, therefore, seek our and India, where timber thus prepared is found to remedy in the salts, the sulphates, or the chlo-be thoroughly protected against the ant. The rides. Where the work is protected from the establishment is capable of creosoting or otherwise weather they have been shown to do their work with perfect success; while the preservation of timber from fire can be efficiently attained, but for all external purposes, such as railway stations, piles, sleepers, bridges, &c., where the smell of the creosote is no objection, that is the cheapest and

impregnating about 1,000 load of timber per week. They do not, however, contine their attention to the creosote process, as we saw a cylinder just returned from France upon the premises which had just been used for pickling some sleepers for a French railway company in situ with sulphate of

copper, the reason for the adoption of this material being that in the particular district where the railway was situated it became a cheaper process than the creosoting. Messrs. Burt and Co. are themselves manufacturers of creosote at separate establishments, where they disti! the creosote in stills holding about 2,500 gallons each. The first product of the distillation is naphtha, and light oil used for manufacturing benzole; secondly, the creosote used in these processes, the residue being pitch. We need not say that the whole success of the process depends upon the quality of the creosote employed, for which we have thus a most desirable guarantee.

Having thus generally described what we saw going on, we entered upon the question with Mr. Boulton as to the practicability of rendering timber uninflammable. He said at once that it was perfectly possible, that he had conducted more than one set of experiments with that sense-but that, as in point of fact there was no demand for fire-proof or uninflammable timber for ordinary purposes, the matter does not now occupy his attention; he had, however, ascertained that by treating the timber with two separate solutions, the effects of which he has already tried, an absolutely uninflammable material can be obtained at a very moderate expense, and the cost of preparation would not exceed about 15s. per load. As we have elsewhere remarked, while people can insure, they will not take constructional precautions against fire, otherwise we should think it well worth the attention of public authorities as well as private individuals, to ascertain some satisfactory means of rendering uninflammable the timber employed in building, in towns especially, for if all houses were built of fire-proof timber, the number of house fires would be almost indefinitely reduced. Warehouses of course are subject to the same remarks, but then the nature of their con

tents much affects the nature of the risk.

what similar way in a vacuum and under pres- £15 to £16. Copperas: dry, brisk, at 52s.; green
sure, is used for timber, canvas, cordage, cotton, and rusty in fair enquiry, at 50s. to 53s. Arsenic
Acid oxalic
and woollen goods, for preserving them from dry at £6 15s. to £7 for fine powdered.
rot, mildew, moth, and premature decay, and has unchanged, at 73d. to 8d.; tartaric, firm, at 1s. 3 d. to
also the property of rendering wood uninflam- 18. 4d.; sulphuric, at £3 15s. Magnesia: Epsom
salts at £4 10s. to £4 15s. for refined. Oils: olive,
mable, and, as a curious instance of its success- better, £49 to £51; pure white Norwegian cod-liver
ful application, we may quote a report of Mr. oil at £9 10s. per barrel. Pitch: dull, at 17s. Ben-
Bastable, of the Metropolitan Wood Paving Com-zole: the demand is not active, and buyers offer
pany:-

"Have had many thousand square yards of wood paving Burnetised (for which they had a license). The company were obliged to keep a very large stock, and the paving so prepared when closely stowed for any length of time was found to be perfectly free from decay."

On the question of uninflammability some experiments were conducted at Portsmouth Dockyard by order of the Lords of the Admiralty, with the following result:-"It appears that some of the prepared woods, especially the Canada pine, have resisted ignition into flame to an extraordinary degree." We are of opinion that yellow pine timber prepared in this way might be used most beneficially not only for magazines and lightroom bulkheads, but also for all the bulkheads of a ship.

Burnetised_canvas has been used for many years by the Peninsular and Oriental Steam Navigation Company, the Hon. Board of Customs, Trinity Board, several members of the Royal Yacht Squadron, and other yacht clubs, also in India by the East Indian Railway and other companies for the preservation of waggon-covers, &c.

We have thus given an account of the principal establishments which are now in operation in London on an extensive scale. We have recently alluded to Colonel Szerelmy's process, which has been undoubtedly successful, but has not obtained an important commercial position, and we have only to say in conclusion that for all out-door purposes the creosote process, as carried out by the There are several large establishments of a firms above alluded to, appears to be all that can similar character in London, notably Mr. John be desired for efficiency and also for economy. Bethell's, but as the process applied is almost pre- its smell renders the employment of creosote imWhile for house building or indoor work, where cisely similar, the above description may be taken to apply. But his operations appear to be spread possible, Sir W. Burnett's process, or the sulphate over a very wide area; he has five pressure tanks of copper solution, appears to be the best at our and establishments for creosoting in England, two command; but, as we before said, the commercial in Scotland, two in Ireland, three in Belgium, and demand for fireproof timber for ordinary purposes two in Holland, and from some papers published is not sufficient to make it an undertaking of imby him we find numerous instances of the success portance, though we cannot help thinking that it of the creosoting principle in tropical countries, is a subject to which the attention of architects, where the wear and tear upon sleepers was about engineers, and public bodies might be devoted 1 per cent. in two years, while on the Madras with the greatest advantage." Builders' Trade Railway the loss in native uncreosoted timber, from the ravages of the white ants, was 33 per cent. On the 12th May, 1868, Mr. Boulton presented to the library of the Institution of Civil Engineers three pamphlets dated 1863, 1864, and 1865, being the fourth, fifth, and sixth reports of (From J. Berger Spence & Co.'s Manchester Circular, a Commission of Engineers and other members of the Royal Academy of Amsterdam, appointed to report upon the dangerous and destructive ravages of the Teredo Navalis upon the timber used in the construction of dykes round Holland; and Mr. James Town, in St. Helena, the colonial engineer, reports the perfect success of the process in a district "where the white ant abounds," and is terribly destructive.

Mons. Crepin (Ingenier des Ponts et Chausse) in a report incorporated in the Annales des Travaux Publiques de Belgique, upon some experiments conducted with creosoted timber, from

1857 to 1864, at Ostend, says :

"The experiment, I believe, may now be taken as decisive, and we may conclude that well creosoted fir timber, prepared with creosote oil of good quality, is proof against the attacks of the Teredo. The wood has retained all its elasticity, and has acquired a density it did not possess in its unprepared state."

Mr. John Coode, engineer-in-chief to the Port

Circular."

WEEKLY CHEMICAL, MINERAL, AND
METAL REPORT.

August 15.)

considerably lower for 30 per cent. Guano: best Peruvian, £13 17s. 6d. to £14 10s. Disinfectants : patent, at £5 for domestic and sewage purposes; carbolic, £10. Pyrites: no alteration, prices ranging from 6d. to 74d.: calcined Spanish, at 43s. 6d. R.C. Lime: bleaching powder rather easier, at £8; super-phosphates remain firm, at £4 5s. to £4 10s.; mineral phosphates, 56s. to 60s. for 65. Manganese: at 80s. for 70. Iron ore: in increased request; hematite, at 13s.; oolitic, 6s. 9d. to 8s. 6d. in Staffordshire, and 2s. 9d. free on rails.

METALS.-Iron: Scotch pig firmer, at 49s. 11d. to 51s.; Cleveland nominally 51s. 6d. and 52s. for forge 4, to 56s. and 56s. 6d. for No. 1; Welsh bars, £6 15s. to £7; Staffordshire bars, £7 10s. to £8; Hoop iron, £9; gas tubes, 60 to 67 off list; boiler tubes, 40 to 423. Copper officially reduced; English tough ingot, £70 to £71; Chili slab, £63 to £64. Tin: Advanced in price; English ingot, £127 to £129; straits, £128 to £129. Lead: selling treely and likely to be higher; best English soft pig £20 10s. Spelter: unchanged; English, £19 15s., to £20; Silesian, special brands, £19 10s. to £20.

Correspondence.

THE MARTINI-HENRY RIFLE.
TO THE EDITOR OF THE "MECHANICS' MAGAZINE."
SIR,-While fully agreeing with the remarks in

your last issue as to the hypercritical nature of
rifle, urged by the Paris gunmaker, I must say
some of the objections against the Martini-Henry
that his opinion as to the general unfitness of the
arm would be endorsed by most of the gunmakers
here who have any experience of the gun in ques-

tion.

Looking at it in the point of view which first presents itself to a gunmaker-the comparative facility of construction-it has proved to be one of the most expensive breechloaders made in Birmingham. Though it has been before the public for some time, and several makers have tried their hands at it, the price of a military gun is now about £8, and £12 for a better description of gun suitable for target or sporting purposes, while there is no difficulty in getting other military guns made, in the same experimental stage, for £4 or £5. That a similar difference will obtain when the guns are made on the large scale is certain, for the Martini-Henry arm will require specially heavy machinery for punching and drifting the breechbox. But this additional cost would be a slight drawback if the gun were markedly suTHERE are few alterations in the chemical trade perior to its competitors, which have increased worthy of note in our last week's circular. A per- greatly, both in number and in quality, since the ceptible improvement in the state of home affairs award of the "Committee." Advantages the gun has taken place, attributable in a great measure to possesses, no doubt; simplicity of movement and the firmness of Government to maintain the rights effective extraction of the cartridge being the chief of neutrality, and also to the suddenly altered aspect-perhaps the only ones. In form the gun is of affairs on the Continent. The orders given out for home consumption have been fully as numerous as last week, and manufacturers have no reason to complain under the circumstances. Soda crystals are in stronger enquiry; but bleaching powder is scarcely in such good demand as last week, while soda ash remains firm. There have been a few orders for abroad, an indication which cannot fail to be satisfactory to those interested; and should the prevalent opinion that the war will be a short one be verified by subsequent events, the chemical trade in England will not suffer the serious check at first imagined. In minerals the trade continues to be remarkably stiff, and prices are, if anything, firmer for some of the staple articles. A slightly better market may be reported in the metal trade, but

business still continues on the most limited scale.

simply detestable; the lever, a cumbrous and unsightly appendage. They have both had their origin in a land where form is but little studied; and it is curious to see how we have been gradually educated into a toleration of ugliness in the productions from that quarter, especially in arms, which, in all previous ages of the world, have been made to unite more or less artistic shape with the sternest fitness for their purpose. The extraction of the cartridge is well done but somewhat overdone, as has been made sufficiently obvious to all who have had occasion to use the gun for rapid firing in the lying or sitting position, and have had to choose between receiving a succession of empty cartridges in the face, and a

land Breakwater, reports in 1857:-"As an in- Scotch pig iron is improving. In copper the En-highly undignified dodging of the same. Besides,

stance of the successful application of creosote, Iglish smelters have reduced the official list £2 per it is perfectly clear that a solid metallic cartridge, may mention that it became necessary to remove ton, but it is questionable whether or not this has capable of being used several times, is what we some piles that had been down four years, and improved the demand. Tin and lead are improved will ultimately arrive at, and as these cartridges fully exposed from above the level of high water in value. No alteration in spelter. Soda: cream must always be expensive, it becomes an object at to nearly 55ft. under sea water. There was no caustic as before, at £12 10s. for 60; and white at times to preserve the empty casos, which is in no sign whatever of attacks by sea worms notwith- £13 5s. to £13 10s.; crystals, firmer, at £4 2s. 6d. way facilitated by jerking them several yards away standing that we have the Teredo Navalis and to £4 58.; bi-carbonate dull, at £9 10s., and £15 to the rear. The handling of the gun, on which Simmona Screbrans in the bay in great numbers." for refined; saltcake, £3; soda ash, firm, at 1 11-16d. shooting so much depends, is awkward in many Similar reports might be quoted from the Cape to 13d, per degree: sulphate of soda, £3. respects. In a breech-loader the model we should of Good Hope, Italy, Germany, Holland, Belgium, of soda: ranges from £14 to £14 15s. Potash: ever strive to come up to is a perfect muzzlefor muriates there are no quotations excepting for and throughout Great Britain on creosoted timber trivial parcels. Saltpetre: is rather easier than last loading rifle, the construction of which has been week, but 30s. for foreign, and 35s. to 36s. for re- trammelled by no mechanical conditions, and it Another important process still in operation is fined is still obtained. Alum: is exceedingly active, is easy to see that the Martini-Henry falls lamentthat of Sir H. Burnett, previously alluded to, loose lump at £6 5s. and £7 in export barrels ably short of this. In the first place, the hand is but it is of more various application. His ground, at £7. Ammonia: brown sulphate better, made to sprawl over an unreasonable depth of solution, the chloride of zinc, injected in a some-at £13 to £13 10s; white and grey rather dull, at stock, and comes into contact with a large mass

used for railway sleepers.

Nitrate

THE Prussians were unanimous in declaring the Chassepot inferior to their own Dreyse. “It certainly has the wider range," they said, "and sometimes kills a man at the most unexpected distances; but, then, you cannot take aim at above 900 paces, and what is the use of blazing away unless you have a fair chance of doing execution? Besides, the immense range of the gun interferes also with your taking aim at short distances, and the large quantity of powder in the cartridge makes it impossible for anyone to stand the recoil. You cannot properly handle a gun that boxes your ears. We have frequently seen men pressing their guns against their breasts and thighs when firing. If the Chassepot could be pointed and discharged by a machine, it would be a terrible weapon indeed." The mitrailleuse is voted an exceedingly unpleasant thing by the Prussian soldiers, "but then, you see,' W. H. W.-W. T. B.-S. J. L.-L J. W.-W. P.-W. J.--they will add qualifyingly-"they always fire as T. B.-T. W. H.-S. W. J.-W. M. W.-T. J. M.-P. H.- straight as you can go. The moment you turn a W. N. J. little to the right or to the left you are safe. It was always much easier for us to evade the balls than for the French to alter the aim of the mitrailleuses." -Prussian Correspondent of the "Times."