Page images
PDF
EPUB

dered it a most formidable subject for any kind of cultivation.

In several fields of this farm operations commenced on the 9th inst. The first implements which ventured to the attack were the horse cultivators, and they were signally and totally defeated, scarcely a tine remaining whole in any of them after an hour or two's work; the horse ploughs fared better, the casualties reported being few, and the work performed generally of first-rate description. The principul com

peting firms were:-Messrs. Vickars and Co.,

NOTES ON RECENT SCIENTIFIC DIS-
COVERIES AND THEIR PRACTICAL
APPLICATIONS.

NEWLY OBSERVED PROPERTIES OF PARAFFIN-THE

MELTING AND SOLIDIFYING POINTS OF FATS-SEAT
OF THE HYGROSCOPICITY OF SILK-ADULTERA-

that silk from which the gum had been removed ook up as much moisture as raw silk. In each case, and under equal conditions, 12.5 per cent. of moisture was absorbed. Thus Bolley decides that the seat of the hygroscopicity is the fibroin or silk itself.

As a hint to large consumers of salt of tin, we may mention, in passing, that the chemist we have TION OF SALT OF TIN-NEW ALLOYS FOR SPOONS just quoted has examined a specimen of the salt, which he found to be adulterated with 17 per cent.

AND FORKS.

of sulphate of magnesia. In appearance this adulterated salt could not be distinguished from the genuine article.

PARAFFIN, generally regarded as one of the
most stable and unchangeable of bodies, has
been found by Bolley to be subject to alterations
The analysis of a few alloys in use in Paris for
which are worthy of attention. In the first place, spoons and forks, and said to be unusually good
it seems to be liable to oxidation, like ordinary or-in appearance, has been made by a German chemist.
ganic fats. For example, Bolley took a specimen of The first, a beautifully yellow alloy, is really
aluminium bronze, and is composed of 89-3 parts
paraffin fusing at 53deg. Centigrade, and having of copper and 10-5 parts of aluminium. The second
the centesimal composition-carbon, 85-61; hy-is also a gold-resembling alloy, and has been named
drogen, 14-69; and kept it exposed to air, and
"orcide." This is composed of 79-7 parts of copper,
heated to 150deg. Centigrade for eight days. In 13-05 parts of zinc, 6-09 parts of nickel, with
the course of this time, the paraffin originally last-named are no doubt accidental ingredients.
0.28 parts of iron, and 0-09 parts of tin. The two
white became browner and browner, and was at last The third is a beautiful white metal, very hard,
changed into a tough, doughy, blackish mass. A and taking a beautiful polish. It is composed of
good deal of this mass was unaltered paraffin soluble 69-8 parts of copper, 19-8 parts nickel, 5.5 of zinc
in absolute alcohol; but after the removal of this and 4-7 of cadmium.

Thus,

Ball, Boby, Ransomes and Sims, Hunt and Picker-
ing, Hornsby, and J. and I. Howards, and the
classes of ploughs experimented with on the 9th,
10th, and 11th were the usual deep and general
purpose wheel ploughs, subsoil wheel ploughs, and
this year, for the first time, for many years, at
least, the swing plough, in both the light and
general purpose varieties. The work with these
implements progressed steadily throughout the
three first days, of the trials, and attracted,
perhaps, the lion's share of popular interest, so
far as could be judged from the number of spec-
tators who congregated to watch the splendid
teams, and implements, and the handiwork of the
first rank of agricultural labour. It is scarcely
our province to comment on or criticize the
performance of experts in an art which is not
a dark brown residue was left which consisted in
our own, and we, therefore, leave to the judges
the position to be assigned in point of merit to 100 parts of carbon, 7004; hydrogen, 10-25;
each of the contending ploughs, and turn to the oxygen, 19.72. Other changes are produced by
more thoroughly mechanical apparatus connected the continued action of heat on paraffin.
with the steam ploughing trials, which commenced in a specimen which first boiled at 300deg. Centi-
in a somewhat preliminary manner on the 9th, and
have continued to the great advancement of our grade, a strong evaporation was afterwards re-
knowledge in this subject, and the great interest marked at 150deg. Centigrade. These facts will
of all present for the last five days. The firms be of interest to those who employ paraffin baths,
appearing at this year's competition are, first and
foremost of course, John Fowler and Company, of and, as Bolley suggests, may have important bear-
Leeds, with no less than five traction ploughing ings on the industry of the body. Paraffin is most
engines, about twelve balance ploughs and culti-likely a mixture of various hydrocarbons with
vators, two or three disc wheel anchors, one of various boiling and melting points. Those speci-
their new seventeen-tine turning cultivators, har- mens which have the highest boiling point have
rows, water carts, &c., &c., in all about 300 tons of also the highest melting point, and from this cir-
machinery, twenty-five men, a movable house for
their accommodation, and, we need hardly say, a
cumstance it is fancied that a hard paraffin can be
competent staff of managers; Messrs. Howard produced at will.
Brothers, of Bedford, with a set of their well-
known tackle and cultivators, driven by one of
Clayton and Shuttleworth's engines; Messrs. Avel-
ing and Porter, of Rochester, with one of their
own traction engines working a Fowler's drum and
gear on the roundabout system, in which they
also employed their own travelling porters, this
year perfected so as to form a real addition to
useful steam ploughing machinery; Messrs. Tasker,
working Clayton and Shuttleworth's traction en-
gine with their own winding drum and Smith's
cultivator with roundabout gear; Messrs. Hayes
and Son, of Stoney Stratford, with their own
portable drum and apparatus in general, with the
exception of the cultivator, which, as in Messrs.
Tasker's case, was on Smith's principle.

ON THE RATE AT WHICH CHEMICAL
ACTIONS TAKE PLACE.*

BY MR. A. VERNON HARCOURT, M.A.
HE science of chemistry may be defined as

The science which investigates the relations
of the different kinds of matter one to another.
The conception of different kinds of matter,
each of which has its particular character, its
own colour and crystalline form, its own hardness
and brittleness or the reverse, its own conducting

powers, its own specific heat and specific gravity; each of which is homogeneous, the smallest particle and many other peculiarities of its own, and having all these properties equally with the largest mass, is the fundamental conception of chemistry. And the whole world to a chemist is only a mixture of such different kinds of matter, whose mode of aggregation has been and is being determined by physical and vital forces which are foreign to his science, but whose resemblances and differences, and whose changes under changed conditions or by contact one with another, from the subject of his study.

[ocr errors]

In the study of any chemical change there are two things to be discovered: first, the result of the change what kinds of matter have ceased to exist and what have come into existence; and secondly, the course of the change; as to which such inquiries as the following present themselves,-—at what rate does the change occur, and under what conditions? Is it simple, or does it consist of several changes? Are these dependent or independent, successive or simultaneous ?-with many others of a more hypothetical kind as to the molecular nature of the change. A familiar example of this twofold nature of chemical inquiry may be drawn from the case of a fire, a chemical change which has been more watched than any other. We know all that is to be known as to the result of the change, when

we have discovered that the coals are a mixture of

The melting and solidifying points of ordinary fats and fatty bodies have also been studied by Wimmel, whose experiments have revealed some curious inconsistencies, if we may call them so. It is a generally admitted law that among fusible bodies the point of solidification coincides exactly with the point of fusion. This, however, is by no means true in the case of fats. Fats proper, that is, those which have glycerine for their base, solidify at a much lower temperature than that at which they become liquid; and in this respect there is a sharp distinction between fats proper and fatty bodies like spermaceti and bees-wax, which latter solidify immediately below the point of fusion. Perhaps the most curious result of Wimmel's researches is the fact he has established On the 9th, the steam ploughs commenced work that in these cases of retarded solidification there rather later than the horse ploughs and cultivators, is always at the moment of solidification a conand scarcely any regular competitive trial of them siderable elevation of temperature,-in some cases, was organized. At first it was almost thought indeed, almost sufficient to bring the fat back to that the competitions and dynanometer tests would the melting point. It is to be observed, however, be postponed, but on finding that in general the that the greatest elevation of temperature takes tackle was quite equal to the work it had to per-place with the bodies which solidify most rapidly. form, the judges readily decided on carrying out Oil of mace, for example, Wimmel states, solidithe original programme. Throughout the entire fies promptly at 33deg. Centigrade, but the solidifitrials of steam machinery the only parts which cation is attended with a rise of the temperature manifested any serious weakness were the shifting to 42deg. Centigrade, the melting point being anchors of those firms that used the roundabout system of tackle. These almost invariably gave way a little at starting, each furrow sliding over the hard ground, which they would not bite. In some cases they broke under the ordeal of a sudden strain, and, with one exhibitor, whose form of anchor was more angular than any of the others, they scarcely held at all, and were the main cause, at the great time run on Saturday, of his being unable to complete the stipulated quantity of ploughing. On Thursday, regular competitive trials were instituted, but Messrs. Tasker and Messrs. Howard did some good cultivating, which was timed by the judges, and the other exhibitors got into position, and worked a little during the afternoon. The 10th, so far as steam ploughing as fat. The two lines of inquiry thus indicated have The was concerned, was devoted to a series of experi- A great deal was said in England some years been pursued with very unequal vigour. ments with Messrs. Fowler's machinery, exhibited ago on the subject of "silk conditioning," or the study of the results of chemical action has engrossed under three different modes of working. estimation of moisture and other matters in raw silk. the attention of chemists almost to the exclusion And, indeed, so Silk, as is well known, strongly attracts moisture, of the study of their course. and Bolley has recently made some experiments to great is the number of different kinds of matter, ascertain the seat of this hygroscopic property. all capable of undergoing a multitude of changes It has generally been supposed to reside in the by the action of heat or electricity or by contact gum with which raw silk is enveloped. Bolley shows, however, that this is an error, for he found * Read before the Royal Institution of Great Britain.

It would be impossible, considering the present incipient state of the proceedings, to enter into a critical investigation of the show. We therefore defer until our next number a detailed account of those objects possessing an especial interest for our mechanical and agricultural readers.

45-5deg. Centigrade. In palm oil, which solidifies
more slowly, the rise is not so considerable.
There is another curious difference in the appear-
ance of fats and fatty bodies when heated. Some
fats-beef and mutton suet, for example-only be-
come clear and transparent when heated far above
their melting points, while spermaceti and bees'-
wax become transparent long before they melt.
Writing of fats, reminds us that Bolley has shown
that benzole or light petroleum oils may be used in
the extraction and estimation of unsaponified fats
in soaps. A soap carefully dried at 100deg. is so
very slightly soluble in these menstrua that for
practical purposes the amount dissolved may be
disregarded, and all extracted may be considered

various hydrocarbons with a small quantity of
metallic salts, that the air is a mixture of oxygen
and nitrogen, and that when the fire has burnt out,
there exists, instead of so much coal and so much
air, a quantity of carbonic acid and water, the
salts, which form the ash, and the nitrogen remain-
But there is still much
ing mainly as they were.
besides this to be found out as to the burning of
the fire. How, for example, is the rate at which
it burns, affected by the draught, or by the density
of the air, or by the breaking up of the fuel, or by
access of the sun's rays? What are the substances,
formed from the heated coal, which actually burn?
Does the reduction of the products of combustion
by carbon play an important part in the phe-
nomenon? Such questions as these relate to the
course of the chemical change.

bution and transformation.

results obtained in many series of such experi-
ments are given in the "Philosophical Transac-tremely active reaction is produced, and the refining
tions for 1866," p. 206. The general conclusion minutes only, when the copper to be refined is not
is operated in a very short time, often in a few
to which they lead is that the total amount of
very impure. The air may be introduced into the
change occurring at any moment is directly pro- midst of the copper bath in various ways, but the
portional, all other conditions being alike, to the most practical mode is to pass it through the tube at
the centre of the roof of the furnace. This tube
amount of permanganate in the solution.
may be readily raised out of the bath when it is not
required to introduce air, and it always remains at a
sufficiently high temperature to prevent its breaking,
as it would do were it subject to sudden variations
of temperature. It is essential that the treatment
should extend beyond the period of oxidation, and
when the metal on examination is found to be of a
deep or brick-red colour the refining is complete,
after which the metal is treated exactly as in
ordinary.

with others, giving rise thus to new kinds of
matter capable of similar changes, that this part
of the science appears absolutely boundless. The
direction which chemistry has taken in conse-
quence of this superabundance of materials may,
perhaps, be contrasted with that taken by physical
science. If the number of distinct physical forces
met with in nature, such as gravity, magnetism,
The last chemical change which has been investi-
electricity, heat, light, &c., instead of being gated from this point of view is that which takes
quite a small number, had been a large number, place when dilute acid solutions of an iodide and a
and these forces had proved to be convertible not dioxide, such as barium or sodium dioxide, are
only one into another but into an infinite variety mixed together. By arranging suitably the dilu-
of other distinct forces, physical experimentalists tion, acidity, and temperature of the solution, the
might have occupied themselves wholly with esta- change may be made to proceed at any rate that
blishing the transmutations of one kind of force is most convenient for measurement. One of the
into another and creating new modes of force, products of the change is iodine, a substance for
Dr. Le Clerc gives the following as the theory:-
instead of studying minutely, as they have done, which we have, in its action on starch, a most
the conditions under which the existing forces are delicate test. By bringing a small known quan- than at the commencement of the operation, still
The bath of metallic copper, although much purer
produced, and the laws which govern their distri-tity of hyposulphite into the liquid, all the iodine contains sulphur, arsenic, antimony, and iron.
that is formed by the gradual reaction of peroxide Under the influence of the air introduced into the
and iodide is reconverted into iodide, and this bath excessive oxidation takes place, whereby the
continues till iodine enough has been formed to sulphurous, arsenious, and antimonious acids are
remove all the hyposulphite. As soon as the disengaged, oxides of copper and iron being also
last particle of hyposulphite has been removed produced in the form of scoria. Combinations of
(converted into tetrathionate), free iodine ap-tained more or less arseniated. An important point
oxisulphuret of copper and antimony are also ob-
pears in the solution, and the moment of its ap- to be noted, which is also well known, is that, by ex-
pearance may be noted by carefully watching tending the oxidation, which may be readily done, a
the colour of the liquid. By adding successive large quantity of oxide of copper may be obtained,
quantities of hyposulphite, and observing the in- which has the property of giving up its oxygen to
terval which elapses between successive reappear- foreign matters, and in this manner conduces to the
ances of the blue colour of the iodide of starch, it reduction of the copper, The production of the
is possible accurately to determine the rate at protoxide of copper in superabundant quantity neces-
which the change is proceeding. An account of a sarily causes a considerable loss of copper, which
number of experiments made in this way and of their combine under the form of complex silicate of iron
results is to be found in the "Philosophical Trans-nical, formed by the influence of the air insufflated
and oxysulphuret of antimony, more or less arse-
actions for 1867," p. 117. Each set of observa- into the metallic bath. For this reason, when, after
tions determines at what rate the dioxide is reduced having introduced the air, the metal assumes a deep
under certain definite conditions; and by making brick-red colour, Dr. Le Clerc takes the precaution to
different series of experiments, in which the seve-add to the bath a mixture of from two to five per cent.
ral conditions affecting the rate of change are sys- of charcoal and lime and to well stir them. In this
tematically varied, it is possible to discover the manner he obtains the complete reduction of the sili-
laws of connection between each of the conditions cate, and all loss of copper is thus entirely prevented.
and the amount of change. Having discovered Immediately following the action of this mixture
these laws, our knowledge of the change is so far the refining process is proceeded with in the ordi-
complete, and we can predict with certainty the ary way.
time that would be required for any given amount
of change under any given circumstances.

It is, however, not only the vastness of the chemical field, and the particular satisfaction which so solid a result as the creation of a new kind of matter brings to the mind of the investigator, which has led to the neglect of the study of the course of chemical changes. This study is beset with peculiar difficulties, and indeed, out of the vast number of chemical changes whose results are known, there are but very few whose course can readily be observed. The principal reason of this is the velocity with which such changes take place, and this velocity is apt to be the greatest in the case of the simple chemical actions which are most suitable for investigation. Either, then, we must contrive some mode of estimating a very great velocity, as has been done for the measurement of the rate at which light and electricity travel, or we must select a change-and this the variety of chemistry makes possible-which proceeds at a rate convenient for observations.

A CURIOUS INVENTION. MAGINATIVE persons should by all means read contemporary:-A new and singular method of the following, which we copy from an American utilizing the forces of air and water has just been patented in Illinois, and applied to the propulsion of vessels in Lake Michigan. The invention is founded on the well-known laws of atmospheric pressure, by which a column of water can be sustained at a heiglit of 33ft. The inventor employs steam instead of air,

Examples of the different velocity of chemical changes are furnished by the precipitation of a barium and of a calcium salt from their solutions upon the addition of a sulphate. With the former, the change is apparently instantaneous. The result is known, but the course cannot be observed. With the latter, the change is gradual, and it would be possible to determine its rate at different temThe following propositions embody the principal peratures and with different quantities of the two conclusions to which the examination of these cases salts in solution. The decomposition of a hypo- of gradual chemical change has led :-1. The rate sulphite in an acid solution is another example of at which a chemical change proceeds is constant a gradual, observable change. We may compare under constant conditions, and is independent of also the reduction of a chromate by a sulphite and the time that has elapsed since the change comby an oxalate. The former occupies no appreci-menced. 2. When any substance is undergoing a able time; the actual time is, doubtless, greater in chemical change, of which no condition varies, exa more dilute solution and at a lower temperature, cepting the diminution of the changing substance, thus gaining a great increase in the force of presbut we cannot discern any difference. But with the amount of change occurring at any moment sure, and his idea was originally to furnish an endan oxalate for reducing agent, though the final re- is directly proportional to the quantity of the sub-less water power in places where only a limited sult of the change is the same, the action takes a amount of water can be obtained-that is, by using stance. 3. When two or more substances act one the same water over and over-the cost of the steam long time to accomplish itself, and it would be upon another, the amount of action at any moment used in condensation being only one-third the cost quite practicable to observe in what way different is directly proportional to the quantity of each of of attaining equal power by the use of the ordinary the substances. 4. When the rate of any chemical steam engine. There is but one of these machines But, in order to discover the laws which govern change is affected by the presence of a substance, in operation at Batavia, Illinois, which makes twenty the rate of any chemical change, some exact mode which itself takes no part in the change, the acstrokes per minute, raising two barrels of water of measuring the rate is necessary. It remains to celeration or retardation produced is directly pro- into the reservoir at every stroke. From the resershow how this may be accomplished in certain portional to the quantity of the substance. 5. The voir it falls upon an overshot wheel, or may be made cases. A solution of ammonium nitrite, heated to relation between the rate of a chemical change octo pass into a turbine wheel, and thence into a

circumstances affect its rate.

a temperature of about 80deg. C. in a flask pro-curring in a solution and the temperature of the cistern below, from which it is again raised by the vided with a gas delivery tube, gives off a quantity solution is such, that for every additional degree of nitrogen, which may be collected over the pneu- the number expressing the rate is to be multiplied matic trough. By keeping the temperature con- by a constant quantity. stant, and collecting the gas evolved during successive equal intervals of time in similar cylinders, it is possible at once to show the regular diminution in the volume of gas which is caused by the constant diminution of the quantity of salt in solution.

the quantities of gas with accuracy, it would be possible to discover the relation between the amount of change going on at any moment and the amount of salt in solution, and, also, by making the experiment at different temperatures, to discover how the temperature of the solution affects the rate at which the action takes place.

REFINING COPPER.

apparatus show a saving of two-thirds of the fuel same agency. The experiments with this curious used in the ordinary application of steam, besides doing away entirely with the danger of explosions. The invention, as improved by a Michigan man, consists in the application of the process to the propulsion of steamers and propellers-the overshot wheel, with steamboat paddles of the usual sort being attached in the former class of vessels and the the latter. It is claimed by the inventor that he will need to carry in his elevated reservoir no more water than is usually carried in steamboat boilers on the old plan, while he dispenses with the cumbrous and complicated engines entirely-that he can attain any required power--that he can greatly diminish the risks of fire as well as explosions, inasmuch as the water carried in the reservoir can be rapidly conveyed by means of hose pipes to any part of the vessel, and also that he can greatly diminish the risks of sinking, because the pumps which raise the water can instantly be connected with the hold of a vessel when a leak is discovered. He claims also to do away entirely with the jerking motion of the engines now in use, as there is no "dead centre" on a water wheel.

And, by making the experiment and measuring The rownify burn indented by Dr. Le Clerc, of turbine wheel, connected with propeller blades, in HE following improved process of refining copper 29, Boulevart St. Martin, Paris. Black copper in a more or less impure condition is subjected to the action of heat in a reverberatory furnace, as is ordinary, and immediately it has reached a sufficiently high temperature to begin to soften, water is projected on the heated metallic mass in the form of very fine jets or small rain until the complete fusion of the metal is obtained, when the supply of water is stayed. SupThe reduction of a permanganate by an oxalate posing the cupreous mass subjected to the action of in an acid solution furnishes another case of a heat contain copper, iron, sulphur, arsenic, antimony, gradual measurable change, and has been more lead, or tin under the influence of the high temperafully studied. Here it is possible to start the ture, the water on coming in contact is decomposed change at any moment by adding the measured and forms sulphuretted, arseniated, or antimoniated quantity of permanganate to the other ingredients hydrogen, which disengages. The oxygen acts on and mixing rapidly. It is also possible to stop it the copper, iron, and other fixed metals, and forms at any moment by adding a solution of iodide to oxides which derive silica from the sides of the the mixture; and the iodine which is set free by furnace and pass into the form of scoria. A small amount of sulphuric, arsenious, and antimonious the action of the residual permanganate corresponds to it in quantity and can readily be esti-acid is produced which disengages in the form of vapour. Immediately the copper is completely mated. By making a number of such experi-fused, Dr. Le Clerc places a tube of refractory clay ments, differing from one another only in the in the metallic bath, the diameter of which tube is time during which the gradual change is allowed proportionate to the quantity of copper forming the to proceed, its course may be traced throughout bath. This being done, he projects a large amount with any required degree of minuteness. The of atmospheric air through the tube, when an ex

THE SCIENTIFIC WONDER.-Have you seen it ? It magnifies 32,000 times. Price thirty-two stamps (post free), with book of full instructions. To be had only from A. McCulloch, Philosophical Instrument Maker, 18, Blucher-street, Birmingham.

N.B. For further particulars, see Advertisement in this paper, page 1, column 2, headed "Scientific Wonder.”—[ADVT.]

[merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][graphic][merged small][merged small][subsumed][merged small][merged small][ocr errors][graphic][graphic][merged small][merged small][subsumed]

HYDRAULIC PRESS VALVES.
R. J. B. FENBY, of Birmingham, who is well

Mknown to our readers and the public for the small cylinder into which the exhaust pipe opens, the arrow in fig. 1, brings the packing h into the

invention of a very perfect lock, has recently patented some improvements in hydraulic press valves. His invention consists in arranging the parts of valves for opening and closing at pleasure the communication between the feed or exhaust pipes of hydraulic presses and the cylinders of the presses, and thereby establishing a communication between the pump and cylinder when it is wished to raise the ram or plunger of the press, or between the cylinder and the exhaust pipe when it is wished to allow the ram or plunger to make its return motion. Valves constructed according to this invention may also be used for the accumulators of hydraulic presses, and for various other purposes. We will describe Mr. Fenby's invention with reference to a hydraulic press. He connects with the cylinder of the press a small or supplementary hollow cylinder closed at one end; a piston works in this small cylinder. The connection between the two cylinders is by means of a pipe or opening in the side of the small cylinder and about midway between its ends. The feed pipe from the pump opens into the small cylinder at its side near its open end, and the exhaust pipe opens into the small cylinder near its closed end. The piston or plunger of the small cylinder is of the same diameter as the interior of the small cylinder, excepting near its middle, where it is made of smaller diameter, and where between it and the small cylinder is an annular space into which the communication with the cylinder of the press opens. The parts of the small cylinder into which the feed and exhaust pipes open are of somewhat larger internal diameter than the middle part. The range of motion of the piston or plunger of the small cylinder is limited by a collar near its top working in a recess in the gland at the open end of the small cylinder. When the piston of the small cylinder is in its withdrawn position that part of it of small diameter is brought into the portion of the small cylinder into which the feed pipe opens, and a communication is hereby established between the feed pump and the cylinder of the press, the communication between he cylinder of the press and the exhaust pipe being

cut off. When the piston of the small cylinder is
in its advanced position, that part of it of small
diameter is in part brought into that portion of the
and the cylinder of the press is thus put in commu-
nication with the exhaust pipe, the communication
between the feed pipe and cylinder of the press
being cut off.

the press and the exhaust chamber a3, causing the hydraulic press to maintain a state of rest. The piston g being moved in the direction indicated by chamber a2, and thereby opens communication between the lug or connection b and the press, the plain end of the plunger g still fitting the cupped leather packing k, and preventing any access to the exhaust chamber a3. When the plunger g is moved in a direction contrary to that indicated by the arrow in fig. 2, the cupped packing h passes into the small part of the cylinder a and cuts off the feed, the valve passing beyond the neutral position represented, and bringing the reduced part of the plunger g through the packing k, and in part into the chamber a3, thus allowing a free escape of the water from the press.

Fig. 1 in our engraving represents an end elevation of a small valve for a hydraulic press, constructed according to Mr. Fenby's invention, fig. 2 being a longitudinal section, and fig. 3 a side elevation of the same. a is the hollow cylinder of the valve, and g is the piston or plunger working in the cylinder. The cylinder a is provided with screwed lugs or connecting pieces b c d, and a tapped hole e for making the necessary joints or connections with Fig. 4 represents in horizontal section a large the feed and exhaust pipes of the press pumps and valve arranged for working with a secondary valve accumulator. The piston g in the cylinder a carries of smaller bore; fig. 5 is an end elevation of the the cupped leather or collar h, and in the cylinder same. B is the hollow cylinder provided with the a is a cupped leather packing i, which fits the piston required lugs or connecting pieces y for bolting in all its positions. The piston g immediately at down, and with passages C, D, and F for feeding, the rear of the cupped leather h is reduced in dia- exhausting, and coupling to the press. The plunger meter, its extreme end being of the full size, as re- A is made in three parts for the purpose of fitting presented in fig. 2. In addition to the cupped leather on leather collars x and w. At either end of the packing i, the cylinder a is furnished with the valve cylinder are leather collars or packings v and cupped leather packing k. In the gland is a cylin-u; pieces t of wood, india-rubber, or other material drical chamber 12, in which the collar g2 on the are inserted into the recesses in the glands and s piston g works, the collar g acting as a stop to regu- for the ends of the plunger A to strike against. The late the range of motion of the piston; the collar smaller valve X is fixed on the large valve in the g2 is made solid with the piston g. The mode of manner represented in fig. 5, the smaller valve having fixing is as follows:-One of the lugs or connecting communication with the chambers a b and c in the pieces b d being coupled to the pressure pipe leading cylinder of the large valve, the lugs or connecting to the tank of the pumps, the other lug b or d is pieces of the small valve being connected for this stopped off or coupled to the corresponding parts of purpose with the chamber ab c. The valve as the next valve where several form one series. The shown in fig. 4 is in a neutral position. The feed lug or connecting piece c is coupled to the cylinder water being supplied through the passage C passes of the press where the ram moves, and to the ram into the smaller valve X through the pipe d2, and is if the cylinder moves. The cylinder a is provided exhausted from thence through the pipe d2. The with four flat lugs or connecting pieces m for bolting plunger of the smaller valve X being worked with a the valve to a base plate or to the press. fever the water is alternately supplied to and exhausted from the chamber a, and thus gives the plunger A the necessary reciprocating motion for admitting the water to the ram of the press from the feed lug or connection C through the lug or connec tion F, and withdrawing and discharging the water through the exhaust passage D.

In fig. 2 the valve is represented in a neutral position, the cupped leather packing h closing the passage from the chamber a of the cylinder to the opening in the lug or connection c, while at the same time the end of the piston a fitting the cupped leather packing k cuts off communication between

[ocr errors]
[graphic]
[graphic]

H

The finest

THE ART OF BUILDING IN CONCRETE.- better, bats, old bricks, clinkers, glass, and almost

Fig. 6 represents in longitudinal section two be found in the particular locality. single valves arranged for working together where description is made from burnt clay, sand, and a four-ported valve is required to feed and exhaust cement, and the coarsest includes in its composition on both sides of a piston. The valves are coupled stones sufficiently large to come under the designaend to end, as represented, with distant pieces Mtion of rubble work. Every professional man is between them, so that when one is open to exhaust aware that rubble work is one of the strongest the other shall be open to feed, as will be understood descriptions of masonry that can be built. It does by the previous description; the valves may also be not depend for its solidity and inherent strength arranged with the ends reversed. Figs. 7 and 8 upon the insistent weight of each stone, similar to represent on a large scale the gland of the valve, dressed ashlar work, but these qualities are imparted fig. 4, fig. 7 being a longitudinal section, and fig. 8 to it by the universality of its cementation-the an end elevation of the inner face of the same; the reticulated nature of its union. The stones do not figures exhibit the shape of the recess M formed for adhere to one another solely by the medium of vertical supporting the cupped leather packing marked u, and horizontal joints, but are cemented together by in fig. 4. joints running in every possible direction. Not the least meritorious feature in Mr. Tall's principle is that any kind of stones, the rougher and sharper the any kind of hard refuse, can be safely and profitably utilized. Bulk for bulk, the cost of the value of Q in our fundamental equation is evidently much less NOR some time back much attention has been than that of Q, supposing it to represent an equivalent directed to the application of concrete, beton, amount of brickwork; and since a less quantity of and its many varieties, to those constructive purposes concrete will suffice to give the same strength as a for which previously brick and stone were regarded greater quantity of brickwork, the saving in the cost as the only suitable materials. We are not now conof material is apparent. We now come to the other cerned with the employment that has been made of item Pl in our calculation. In the first place, we these substitutes upon a scale of magnitude, em- will briefly describe the method of using the appabracing the construction of sea-walls, harbours, ratus. It consists of a frame composed of uprights jetties and similar works of corresponding dimensions. at the corners, and longitudinal panels fitting in Our remarks at present are confined to those ex-between, and enclosing a space equal to the thickness amples in which attempts have been made to super- of the intended wall. Where there is a long length sede the use of brick and stone in ordinary dwelling- of wall to be built, it is obvious that the panels, houses, warehouses, and stores, by the application which consist of planks laid longitudinally, would

FOR

TALL'S APPARATUS.

THE

AMERICAN IMPORTS.

into the United States in reports ins of the your 1866 have amounted to 84,067,354 dollars, a decrease of more than 11 per cent., as compared with the first three months of 1867. Deducting gold and silver, the imports of merchandize were of the value of 80,468,415 dollars, a decrease of nearly 13 per cent. In many articles the decrease is very groat; cotton, and manufactures thereof, declined from 11,166,544 dollars in the first quarter of the year 1867 to 5,517,302 dollars in the first quarter of 1868; iron and steel, and manufactures thereof, from 6,687,728 dollars to 3,820,055 dollars; wool, and manufactures thereof, from 13,029,161 dollars to 8,392,928 dollars; flax, and manufactures thereof, from 5,744,546 dollars to 3,604,154 dollars; earthen and chinaware, from 1,306,124 dollars to 799,205 dollars, fancy goods, from 1,188,313 dollars to 640,026 dollars; hides and skins, from 3,557,221 dollars to 2,593,585 dollars; paper, and manufacdollars; wines and spirits, from 1,404,832 dollars tures of paper, from 614,600 dollars to 301,635 to 983,304 dollars. The imports of some articles of first necessity-tea and sugar, for instance-greatly increased.

of concrete. The first principle that must be adhered sagg, were they not supported at intervals. This is OF

If

SALMON FOR NEW ZEALAND.

to in all attempts to supersede any recognized prevented by the introduction of intermediate uprights, and time-honoured system of construction is that or stiffening pieces, as they might be termed, into the total cost of the proposed novel method must which the ends of the panels slide. These stiffening not exceed that of the old. The total cost obviously uprights act precisely the same part as the T-iron consists of two items-one, the price of the material, stiffeners do to the sides of a plate girder. The and the other, that of putting it together, the price frame being set up and truly levelled, the space of the workmanship. This first principle may be between the panels is filled in with the concrete for expressed mathematically in very simple terms. a height of 21in. all round. Wood blocks, slightly Q represent the quantity of material required in one tapering, are inserted in the material, where joists, system, the older one for instance, and P the cost of sills, and other work is to be placed, and the building the workmanship attendant upon Q, then P and Q carried up uniformly. So soon as the 21in. is represent the total cost of erection by this method. finished the panels are removed and shifted up to Let Q'equal the quantity of material demanded by their next position upon the uprights, and so on the new system, and P' its cost, then PXQ will until about 6ft. in height is gained, when the uprights manifestly represent the total cost. In order to themselves are shifted up, and so on to the compleensure a fair trial to any new method of construction, tion of the work. The frame is in separate pieces, the maximum value that may be given to PIXQ' is and its putting together and taking asunder a very P1×Q=PXQ. Unless this fundamental principle simple operation. We cannot, however, but consider be adhered to, there is no practical use in endeavour- that a large portion of the timber in it might be ing to introduce to the public any proposed new advantageously replaced by iron. By the skilful and method of construction with the slightest chance of judicious use of angle iron the whole arrangement making it pay. Either of the two items, P or Q, might be rendered lighter and more permanent. It may be separately greater or less than Pi or Q but is easy to perceive that the apparatus is susceptible there must be a collective equality in any case. A of improvement, which will doubtless be given to problem that has been for a long period presented to it as it comes to be more generally adopted." the architect and builder is, What is the minimum Notwithstanding that one of the items in our price at which dwellings can be erected for working calculation is so much smaller than the corresponding men and their families? We do not ourselves conone having reference to construction in brick, it sider that this is either a fair way of stating the is evident that the other is much greater. In a question or a plan likely to solve the difficulty. We word, it would not pay to employ Mr. Tall's appa-pearance of complete decay, some of the boxes do not believe in what is commonly called "cheap ratus to build one small house, any more than it work," although we do believe in a cheap principle would to employ a steam engine to lift one sack of of work, which is a very different affair. The ques-coals, or a locomotive to draw one carriage. The tion, then, resolves itself into the substitution of framework may be regarded as plant which may be some material which shall be cheaper than those ordinarily used in all similar instances. Concrete has been employed from very early times in this manner, but its application has been not only hitherto confined to very narrow limits in the building house sphere, but it has never received that amount of investigation and attention which the importance of the subject demands. It has never been regarded in a systematic point of view, and the taking out of a patent by Mr. Tall is the first indication that success will attend its adoption, and render its utility not questionable, but undoubted-its application not transitory and fitful, but steady and permanent.

One of the constant and most shallow arguments urged against concrete walls is that they are not so strong as those built of bricks. It is excusable, though barely so, for amateurs and outsiders to put forward such utter nonsense, but when we witness the same statements supported by professional men, the reply to them becomes a species of absurdity. There are abundance of statistics with respect to experiments conducted with a view to testing the breaking weight of concretes and cements at the disposal of those who choose to search for them. We would advise those who are not acquainted with them to become so before they ignorantly draw comparisons between the two methods of construction. Without entering further into this matter, it will be assumed that a concrete wall built upon Mr. Tall's principle is much stronger than an ordinary brick wall built in mortar. It is not, however, taken for granted that it is any stronger than a brick wall built in Portland cement; they are probably of equal strength, and both after the lapse of a certain time participate more in the nature of solid rock than an agglomeration of individual and component parts. The actual nature and constituency of Mr. Tall's concrete may be said to be of a double kind, fine and coarse, with many intermediate shades, as it were, depending upon the character of the gravel or stone to

UR readers will doubtless remember that we recorded a few months since the shipment of salmon and trout ova and live fish to New Zealand. The "Otago Times" announces the arrival of the «Celestial Queen' with her piscatorial freight at Port Chalmers, on the 2nd of May last. The first news was disheartening. The live fish shipped had ceased to be. The gudgeon got bruised and died; the carp succumbed to the heat of the tropics; the tench, by the carelessness of one of the ship's boys, mistaking one bucket for another, were thrown into the sea; and only two oysters survived. A few boxes of ova were opened immediately on arrival, before sending them to the ponds. The first box contained seven ova in a satisfactory state, and so were boxes of Tay salmon and brown trout, especially one of the trout boxes marked with the wellknown initials "F. B The boxes were forthwith carefully transhipped for their destinations. Ten boxes were reserved for an experiment in the Water of Leith, to which they were speedily despatched. Besides the boxes of salmon ova there was one containing the ova of a sea trout. It is satisfactory to know that of this quantity there appears to be a very considerable proportion in a healthy state. On opening their boxes of salmo umbla by the Acclimatization Society it was found that they had been packed very closely, or had become adhesive, and would not separate in the usual way. A few likely ones were separated and kept, but on the whole they were very bad indeed. They had generally the apsmelling quite offensively. The eggs were of a yellow colour, which can be best compared to that of Kerosene seen through a white glass. The trout ova, however, were in a better condition. About a quarter rendered serviceable for a number of similar jobs, but of the quantity had all the appearance of life. Buc which is too expensive to be used upon a very insig- even when those which appeared to be alive were nificant scale. Any person desiring to erect half a examined through a glass tube there was discovered dozen cottages or other small dwellings would find on many a small white streak, which had probably the first cost of the concrete apparatus more than been communicated to them by contact with the repay itself. All concrete work in the wails of dead ova, but which is understood to be a fatal sign. houses must be faced with stucco or plaster on the It was observed that where the moss in which they outside, and owing to the roughness of the material were packed was green the ova were healthy, but the "bite" obtained by the plaster is so good as to those inclosed in moss which had become brown virtually incorporate it with the concrete. There were found to be dead; and in the majority of the would be no danger of it peeling off in patches, as is boxes much of the moss had become dry, withered, constantly the case when stucco is applied upon and moulded. A result similar to this was observed brickwork. On the other hand, there is no absolute by Mr. Ramsbottom and the commissioners appointed necessity for plastering brickwork, provided the to conduct the experiment of introducing the salmon bricks are of a quality sufficiently good for facing into the rivers of Tasmania. It was observed also bricks. All that is really necessary in labourers by the commissioners that the smallest amount of dwellings is to strike the joints, and in a house of mortality was invariably found in those boxes in superior description to tuck-point them. It is which the moss had been most loosely packed and alleged as one of the greatest advantages of this the ova subjected to the least amount of pressure. system that skilled labour may be dispensed with, Great pains have been taken by the Acclimatization and that a common labourer can build up the walls Society to secure a cool pure stream; the society within the frame. This is a point we do not entirely has done all that art can do to aid Nature. Timo coneur in, for care and skill are necessary in building will show the result. Among the contents of the the walls. They cannot be exactly thrown together icehouse on board the "Celestial Queen" was a small in heaps, and the materials left to arrange themselves box containing a dozen of Dorking eggs. Thes in any manner they choose. Skilled labour may be were also intended for the Acclimatization Society, reduced in amount, but it cannot be altogether dis-and have been distributed for hatching. Another pensed with. We shall be glad to witness the item in the list of articles for acclimatization was a further development of Mr. Tall's principle, as it bundle of heather, which looked as if it had just appears to possess all the elements requisite within been plucked from the moors, the bloom being still the limits we have mentioned to ensure the perceptible. of soundness, solidity, strength, and durability in whatever description of building it may be applied to. The manner in which houses are run up with scarcely a whole or sound brick in their entire composition has proved to what ordinary brickwork may come. Any regular systematic method of utilizing concrete as a building material, if scientifically carried out, must attract the attention of both professional men and the public." Building News."

presence

FROM a return just published, it appears that the expenses of the Irish Railway Commissian aunted to no less than £22,505 113. 34. Of this sum th remuneration of three of the commissioners and the secretary was £3,225, the office expenses, printing, and incidental, £2,298 58. 7d., and the travelling expenses, £5,255 7s. 9d.

BLOWING ENGINE AT THE LANGLOAN IRON WORKS. MESSRS. J. AITKIN AND CO., ENGINEERS.

[merged small][merged small][merged small][merged small][graphic][merged small][merged small]

are

The

engines represented in our engravings illustrate are placed the feed pumps, and, when they ar BLOWING ENGINE AT THE LANGLOAN their most recent practice, embodying as they do required, tuyere pumps as well. The steam cylinexcellent proportion and design. There are two ders are each 45in. in diameter and 8ft. 6in. stroke, IRON WORKS. engines coupled at right angles, with a fly-wheel the pistons are each packed with three of RamsHE engines which we illustrate between them. The condensers are arranged bottom's steel rings, placed in a movable ring Tab pair of blowing at the Langloan Iron Works beneath the floor of the engine-room behind the which can be removed to renew the packing when by Messrs. J. Aitkin and Co., of Glasgow, who have cylinders, and the air pump is placed on the top required without withdrawing the piston. long been known in connection with the manufac-of the condenser. The steam and exhaust valves air pump is 26in. in diameter and 4ft. 3in. stroke; ture of engines of this class. There are upwards are of the Cornish type, and are actuated by the bucket and cover are each provided with four of fifty blowing engines of different sizes at the means of cam gearing driven from the fly-wheel disc rubber valves; the cams are made to open the warious ironworks of Scotland and England which shaft through a counter shaft; the steam valves valves by depressing a lever provided with an antihave been erected by the same makers, and the cut off at half stroke. Behind the blowing cylinders friction roller; at the opposite end of the lever is

« EelmineJätka »