pounds), and a little water being added the lids are closed, a small hole being left in each of them; and a considerable number are then placed in a bath in such a manner as to leave the upper part of the tins exposed. This bath contains Chloride of Calcium in solution raised to about boiling point, and whilst the contents of the tins are boiling, the water escapes as steam through the holes punctured in the lids. After a time the air is all expelled, the holes are soldered up, and the tins with their contents transferred to another bath, but raised to 260 degrees, and should any of them be imperfectly soldered they at once begin to leak. After boiling there for some time the meat is in a fit state for being kept any length of time, and it only remains to ascertain whether the air has been perfectly excluded. For this purpose the tins are placed in a dry chamber warmed up to about 90 degrees, and are left there for a time. The workman then gives each tin a light tap at the upper end, and if it emits a hollow sound, indicative of a space below, he is satisfied there is a vacuum and marks the tin as perfect; but should the sound be dull, as though the meat were in immediate contact with the lid, such a tin is not considered fit for retention and is set aside. Meat so preserved is already very largely employed for ships' use, and it is hardly necessary to say that as so simple an operation may be, and is, performed abroad where meat is cheap, as well as in England where it is dear, the development of this branch of industry will have a most important effect upon our meat-supply.

The great desideratum will be to provide a quality of meat suitable for preservation, and as that applies to all systems, whatever they may be, we shall now direct our attention to this phase of the subject. Of the remarkable facilities which exist on the River Plate for the breeding of sheep and cattle we have already spoken, and we would now, in passing, direct the reader's attention to the illustration accompanying this paper, which will convey some idea of the appearance of an Estancia, or cattle-breeding and sheepshearing farm in Uruguay. In the foreground are the cottage with its Corral, or cattle-pen, its store and shearing house, and in the distance, the sheds, wharf, and vessels loading hides, tallow, and wool. These are the chief products of the live stock, besides the calcined bones, which the breeder aims to secure, the flesh being quite a secondary matter, and all authorities are at present agreed that the meat offered for sale on the River Plate is not suitable for preservation and exportation. The reasons are that the cattle is wild and unfit for slaughter, that no attempt on a large scale has been made to breed such as would produce good meat, and that if even the stock sent to Buenos Ayres be of a good description when it leaves the Estancia, it arrives there "miserably fatigued, the effect of which on the meat cannot but be disastrous, as after that its nutritive power is

diminished and it cannot keep," and Mr. Latham considers that "it will take two or three pounds of Argentine meat in its usual condition to equal in nutritive value one pound of English-fed meat." It must therefore be obvious to every reflecting person, that if such meat be exported to England, and arrives here in the best condition, the price at which it is offered, say fourpence a pound, cannot afford a sufficient inducement to purchasers, who would find a better investment for their money in home-grown meat at sevenpence or eightpence per pound. There is, however, nothing impracticable in the way of feeding-up suitable animals, and the land and cattle owners do so for their own use on the farm. Mr. Prange writes to 'The Times': "I have every year reared a small number of oxen for household consumption, and I may safely say that their beef is as tender and juicy as the fine joints I dine off at this hotel."+ "Beef," he further adds, "from the cattle as now reared can be bought in Uruguay at a half-penny per pound; and I shall make a fine business of it, if in a few years I can sell 6,000 oxen, fattened on my land, at 2d. per pound for the best beef."

Seldom have words of so encouraging a kind appeared in the leading journal, and we have no hesitation in saying that as such a result can be attained within four or five weeks' voyage of our shores, the time is not far distant when a large supply of wholesome meat will find its way into our markets. As long as there was no regular outlet for such beef-it being worth in Buenos Ayres less than a penny a pound, and employed only as "charqui," or jerked beef for export to Brazil and Havannah for the use of the slave population-it was not likely that the breeders would trouble themselves to improve its quality. Soon, however, it will come into competition with English preserved meat; and an Estancia has just been sold to a German Joint Stock Company established for the manufacture of the extract of meat, whilst another has for some time been worked by the "Antwerp Liebig's Meat Extract Company."

With respect to the improvement in the breed of Cattle, and the fattening of stock, there appears to be no difficulty whatever. Mr. Latham in his letter to The Times,' and in his excellent work on the River Plate, has discussed the subject fully and impartially,‡ and what he tells us agrees entirely with the statements of the owners of large Estancias. For many years past, English bred cattle has been imported for the purpose of crossing with and improving the native breeds, and on the better regulated Estancias good cross-bred

* Mr. G. Bell's letter to The Times,' October 28, 1867; and 'The States of the River Plate' (p. 140), by Wilfred Latham. Longmans. 2nd edition. 1868. + Morley's.

The States of the River Plate,' pp. 15, 19, 22, 23, 34, 44.

II. ON THE MECHANICAL PROPERTIES OF IRON AND STEEL.

By W. FAIRBAIRN, F.R.S.

HENRY BESSEMER, like his prototype, Cort, has effected a revolution in the manufacture of iron and steel; and the present improvements exhibit a means of development by which the former will ultimately double its strength, and in the state of steel be substituted for purposes of construction. The result of this change, when applied to structural purposes, is considerable, as half the weight of steel is equal in strength, and consequently is cheaper than a given weight of iron. In almost every case where iron is at present used, steel would then be employed: as in the construction of bridges, ships, and other structures to which iron is now applied. It only requires certainty and uniformity of character in its manufacture, to ensure its superiority and extend its application. This has not as yet been accomplished; but the Bessemer process, by depriving the crude metal of its carbon in a separate vessel, certainly tends in that direction; for by this process increased facilities are not only afforded, and new combinations formed, but the introduction of measured quantities of the same metal, containing the requisite quantity of carbon, poured into the converting vessel, appears to be the only true principle on which steel in its varied conditions of ductility, tenacity, &c., can be produced. These quantities, when duly proportioned, indicate the quality of the steel to be obtained from this process, and, when cast into ingots are ready either for the forge or the rolling-mill. From this it will be seen that every description of homogeneous iron or steel may be produced, care being taken to ascertain the exact percentage of carbon requisite to be infused in order to combine with the mass of refined metal.

This process of conversion as adopted by Mr. Bessemer is entirely new, when compared with the old method employed in the converting furnace with the bars embedded in charcoal, which required at least a fortnight for the refined iron to absorb the necessary quantity of carbon to form steel. By the new system steel is produced in the Bessemer vessel in less than twenty minutes, whereby a great saving of time, fuel, and other expenses is effected. As this process is extremely interesting, it may be briefly described as follows:

A quantity of pig-iron, containing an average quantity of carbon, say 5 per cent., is melted in one or more reverberatory furnaces, according to the size of the converting vessel to be used, which varies in capacity from five to ten or twelve tons. When the metal becomes fluid, it is run into the converting vessel, to which is

process. Of the chemical preservative operations we have already spoken at length. At present they do not inspire much confidence where the object is to preserve meat for long voyages, for if there be anywhere in the world a fastidious diner, it is the Englishman of every rank. What improvements in these systems may be introduced concurrently with the production of an improved quality of meat abroad we are unable to say, but we would recommend those who are practically engaged in the rearing of cattle and the preservation of beef to turn their attention to the smoke drying and curing processes already in use. In this case also the cattle must not be too fat, for the fat decomposes more readily than the flesh and of the curing processes known to us, that which appears the most likely to be immediately successful and remunerative is the one by which "Hambro' smoked beef" is prepared. This kind of beef is becoming a great delicacy even in England; and as the breeders on the Plate have, from their associations and connections (many being Germans) peculiar facilities for perfecting the process there, where the raw meat has only a nominal value, we hope soon to see it sent over in large quantities, and of a quality equal to that now imported from Germany.

These are a few of the numerous devices by which it is sought to supply our home market with imported meat of a wholesome and nutritious description, and the reader will perceive that the resources of trade, navigation, art, and science are being brought to bear in the execution of this all-important object. There is no unmixed evil: indeed what we in our ignorance are apt to regard as an evil is often designed by Providence as the incentive to exertion and progress; had it not been for the alarm excited by the cattle plague, it is not improbable that the vast resources of the River Plate and of our own Australian Colonies, to the development of which the energies of the adventurous trader and agriculturist are now being directed, would have lain dormant for years to come, until perhaps, with an increased population, we should have found ourselves reduced to an extremity and exposed to fatal dangers which may now be happily averted.

II. ON THE MECHANICAL PROPERTIES OF IRON AND STEEL.

By W. FAIRBAIRN, F.R.S.

HENRY BESSEMER, like his prototype, Cort, has effected a revolution in the manufacture of iron and steel; and the present improvements exhibit a means of development by which the former will ultimately double its strength, and in the state of steel be substituted for purposes of construction. The result of this change, when applied to structural purposes, is considerable, as half the weight of steel is equal in strength, and consequently is cheaper than a given weight of iron. In almost every case where iron is at present used, steel would then be employed: as in the construction of bridges, ships, and other structures to which iron is now applied. It only requires certainty and uniformity of character in its manufacture, to ensure its superiority and extend its application. This has not as yet been accomplished; but the Bessemer process, by depriving the crude metal of its carbon in a separate vessel, certainly tends in that direction; for by this process increased facilities are not only afforded, and new combinations formed, but the introduction of measured quantities of the same metal, containing the requisite quantity of carbon, poured into the converting vessel, appears to be the only true principle on which steel in its varied conditions of ductility, tenacity, &c., can be produced. These quantities, when duly proportioned, indicate the quality of the steel to be obtained from this process, and, when cast into ingots are ready either for the forge or the rolling-mill. From this it will be seen that every description of homogeneous iron or steel may be produced, care being taken to ascertain the exact percentage of carbon requisite to be infused in order to combine with the mass of refined metal.

This process of conversion as adopted by Mr. Bessemer is entirely new, when compared with the old method employed in the converting furnace with the bars embedded in charcoal, which required at least a fortnight for the refined iron to absorb the necessary quantity of carbon to form steel. By the new system steel is produced in the Bessemer vessel in less than twenty minutes, whereby a great saving of time, fuel, and other expenses is effected. As this process is extremely interesting, it may be briefly described as follows:

A quantity of pig-iron, containing an average quantity of carbon, say 5 per cent., is melted in one or more reverberatory furnaces, according to the size of the converting vessel to be used, which varies in capacity from five to ten or twelve tons. When the metal becomes fluid, it is run into the converting vessel, to which is