To trace the whole process from the tree to the finished block, we shall commence with—No. 1. The straight cross-cutting saw. This is a saw operating very nearly in the same manner as the carpenter's hand-saw. The timber is brought to the mill in long trees, (of elm for the shells of the blocks,) with their sides rudely squared by the chip axe, so as to become irregular obtagons in their transverse section ; these are drawn by the machine upon a long horizontal bench, which is situated in the yard ; and one end of the tree is brought through the window against which the machine is placed, and, being adjusted to their proper place, is cut across by the saw ; exactly the proper length being cut off the end of the tree to form the such of that kind of block for which the piece of timber seems best adapted, either as to its size or quality. This machine is only used for the largest trees.
No. 2. The circular cross-cutting saw, is for ex actly the same purpose as the former is applied only to the smaller trees : It is a very curious piece of mechanism, difficult to be described in words. The timber is brought as before, through the win dow. The saw is a circle, with its axis parallel to the length of the tree. This axis is so mounted in a cu rious form, that it can be moved in all directions, ei ther raised up, or moved sidewise ; but in all these motions its axis continues parallel to itself, and the saw continues in the same plane. The saw continues in rapid motion by the mill ; and the attendant apply ing the saw, by means of turning a handle, to the side of the tree, which it cuts into about one-third the diameter of the saw, and perhaps half through the tree, then he does the same on the top of the tree, next on the opptisite side, and lastly beneath, if it is necessary, till the wood is quite cut across from its different sides. means a tree could be divi ded by a saw which could not be of sufficient diame ter to reach through from any one side.
No. 3. The reciprocating ripping sate. The blocks cut by the last machine are here cut in the direction of the grain of the wood, first into two, three, or snore pieces, in one direction, and then in a direction perpendicular to the former, so as to reduce the logs into the size for the scan ding of 'the yequircd block. This saw is on the same principle as that in common use in America and other countries, and which has often been described ; but the construction of the machine is somewhat different. The largest blocks only are sawn or ripped up by this saw ; the smaller ones being cut in the next machines, which are No. 4. The circular ripping saw. They have four of these, each consisting of a circular saw, projecting partly up through a table similar to a carpenter's bench. The pieces of wood being applied to the saw,
are cut through the length of the grain, and divided into the proper scantling, in the same manner as by the foregoing machine ; but this is applied to the smaller sizes.
These are the machines appropriated for converting the timber, and occupy one of the wings of the build ings. The parallelopipedons which are formed here, are carried to the opposite wing of the mill, where the machines for forming them into blocks are situated. They are as follow : No. 5. The boring machines. The blocks thus sawn out, are fixed into a frame, and two centre bits are appli'ed ; one to bore a hole for the centre pin, and the other, perpendicular to this can be brought to bore a hole for the commencement of the mortice which is to contain the sheave ; the latter borer can be so fixed as to bore either one, two, or three holes, according as a single, double, or thieefold sheave block is wanted.. Five of these machines are used.
No G. The morticing machines are most ingenious and perfect pieces of mechanism, which might be ap plied to many other useful purposes ; each gives mo tion to chisels, which mortice out the cavities for the reception of the sheaves in two blocks at the same time, if single or double blocks ; but in morticing threefold blocks, only one is done at once. Three of these machines are used.
No. 7. The corner saw cuts off the angles of the parallclopipedons which have passed through the above machines. There are three of these machines.
No. 8. The shaping engine is a curious engine, in which ten blocks, previously morticed, and with their angles taken off, are fixed by their extreme ends, be tween the runs of two equal wheels fixed upon the same axis. These having a rapid rotatory motion given them, the blocks are successively brought against the edge of a fixed gouge, which forms the outsides of all the•twelve blocks to the segment of a large circle, which they describe by their rotation with the large wheels. The gouge has also a progressive motion following the curvature the block is intended to have. When this is done, all the blocks, by an in. stantaneous movement, are turned half round, so that the sides which were towards the centre of the circles are now brought outside ; and the whole machine being again turned about, these sides of the blocks are formed by the same means as the former. The shaping machine, therefore, forms the outside of the blocks to their proper figure. They have three of these engines for different sized blocks, though ei ther of the machines will receive several sizes, among which the differences are small and progressive.