"The different processes of the manufacture of tin plate may be described most properly in seven distinct stages. The first begins with the bars of iron which form the plate; the last terminates with an account of the process of tinning their surface. The description is somewhat technical; but a glance at the following heads will enable the reader to comprehend the whole process: -

"1. Rolling is the first and most important point requisite to the production of the latten, or plates of iron, previous to the operation of tinning them. For this purpose the finest quality of charcoal iron is invariably employed, which, in its commercial state, generally consists of long flat bars. These are cut into small squares averaging one-half an inch in thickness, which are heated repeatedly in a furnace, and are repeatedly passing through iron rollers. A convenient degree of thinness having been obtained, the now extended plates are "doubled up," heated, rolled, opened-out, heated and rolled again, until, at length,thc standard thickness of the plate has been reached.

"2. Shearing. - A pair of massive shears worked by machinery, is now applied to the rugged edges of this lamellar formation of iron-plate. It is cut into oblong squares, 14 inches by 10, and presents the appearance of a single plate of iron, beautifully smooth on its surface. A juvenile with a knife soon destroys the appearance, however, and eight plates are produced from the slightly coherent mass.

"3. Scaling. - This process consists in freeing the iron surface from its oxyd and scoriae. After an application of sulphuric acid, a number of plates, to the extent, we shall say, of GOO or 800, are packed in a -iron box, which is exposed for some hours to the heat of a furnace. On being opened the plates are found to have acquired a bright blue steel tint, and to be free from surface impurities.

"4. Cold Rolling. - It is impossible that the plates could pass through the last fiery ordeal without becoming disfigured. The cold rolling process corrects this. Each plate is separately passed through a pair of hard polished rollers, screwed tightly together. Not only do the plates acquire from this operation a high degree of smoothness and regularity, but they likewise acquire the peculiar elasticity of hammered metal. One man will cold roll 225,000 plates in a week, and each of them is, on an average, three times passed through the rollers.

"5. Annealing.- This process is also a modern improvement on the manufacture: 600 plates are again packed into cast iron boxes and exposed to the furnace. There is this difference in the present process from that of scaling-that the boxes must be preserved air-tight, otherwise the contained plates would inevitably weld together and produce a solid mass. The infinitessimal portion of confined air prevents this.

"6. Pickling. - The plates are again consigned to a bath of diluted acid, till the surface becomes uniformly bright and clean. Some nice manipulation belongs to this process. Each plate is, on its removal from the acid, subjected to a rigid scrutiny by women, whose vocation it is to detect any remaining impurity, and scour it from the surface. These multifarious operations, it will be seen, are all preliminary to the last, and the most important of all-that of tinning. Theoretically simple, this process is practically difficult; and to do it full justice would carry us beyond our limits. We shall however, mention the principal features.

"7. Tinning. - A rectangular cast iron bath, heated from below, and calculated to contain 200 or 300 sheets, and about a tun of pure block tin, is now put in request. A stratum of pyreumatic fat floats upon its surface. Close to the side of this tin pot stands another receptacle, which is filled with melted grease, and contains the prepared plates. On the other side is an empty pot, with a grating; and last of all there is yet another pot, containing a small stratum of melted tin. Let us follow the progress of a single plate. A functionary known as the " washerman," armed with tongs and a hempen brush, withdraws the plate from the bath of tin wherein it has been soaking; and, with a degree of dexterity only to be acquired by long practice, sweeps one side of the plate clean, and then reversing it, repeats the operation. In an instant it is again submerged in the liquid tin, and is then as quickly transferred to the liquid grease. The peculiar use of the hot grease consists in the property it possesses of equalizing the distribution of the tin, of retaining the superfluous metal, and of spreading the remainder equally on the surface of the iron. Still there is left on the plate what we may term a salvage; and this is 2 finally removed by means of the last tin pot, which just contains the necessary quantity of fluid metal to melt it off-a smart blow being given at the same moment to assist the disengagement. The "list-mark," may be observed upon every tin plate without exception. We may add here, that an expert washerman will finish 6000 metallic plates in twelve hours, notwithstanding that each plate is twice washed on both sides, and twice dipped into the melted tin. After some intermediate operations - for we need not continue the consecutive description - the plates are sent to the final operation of cleaning. For this purpose they are rubbed with bran, and dusted upon tables; after which they present the beautiful silvery appearance so characteristic of the best English tin plate. Last of all they reach an individual called the "sorter," who subjects every plate to a strict examination, rejects those which are found to be defective, and sends those which are approved to be packed, 300 at a time, in the rough wooden boxes, with the cabalistic signs with which the most of us have been familiar since the days of our adventures in the back-shop of the tinsmith." - {From the Builder.]