"The cinder produced is superior in quality to that which results from the common system; it contains from 50 to 55 per cent, of iron, and is free from phosphoric acid, which frequently exists, and is so injurious in all the ordinary slags: when re-smelted the cinder produces as much as No. 1 and No. 2 cast-iron, and is of as good quality, as the ordinary 'black band' ore of Scotland."

The process was highly commended by the meeting as being simple and scientific, and evidence was advanced to show the iron produced in this mode, to be equal to the best cable iron.

Note Q, Page 196 of Vol. i - To follow the Foot Note.

(Nasmyth's Patent Direct-action Steam Hammer.)

Since the foregoing pages were printed, a valued friend of the author, Mr. James Nasmyth, of Patricroft near Manchester, has brought into successful operation two very important machines, the one the Direct-action Steam Hammer employed in the place of the old helves or lift hammers, the other a legitimate descendant of the above hammer, a machine invented for driving the piles required for the foundations of buildings and coffer dams. The author is enabled to present to his readers some particulars of these machines, which their inventor has been kind enough to write for these pages.

"Fig. 968 represents a general view of the steam hammer, B. is the cylinder in which the piston works, and to the piston-rod which comes out at the bottom of the cylinder is attached the hammer A, high-pressure steam is let in under the piston, which raises it together with the hammer A, to any required height within its vertical range of motion, and in which it is guided by two planed guides KB. the escape of the steam when the valve of the cylinder is opened, the hammer falls on the work that lies on the anvil with the full force due to gravity, and without any loss worth naming from friction; the instant the hammer has given its blow the steam is again 1st in under the piston, and the asms action is repeated with case and rapidity."

"When it is desired to lessen the force of the blow, the steam is 1st in under the piston, ere the fall it complete, so that a cushion of steam is then presented to receive the force, and modify it to any required extent; such is the precision with which this can be dons, that the hammer may be arrested in the most soft sod silent manner even when within one-tenth of an inch of the anvil. The hammer can be thus set to give any definite blows, by the due adjustment of the lever which closes the valve, for which purpose its position is regulated by two long screws seen in the figure; the re-opening of the valve is effected by a small cylinder and piston (at B), on the top of which piston steam is made to act as a most perfect spring."

"When, on the other hand, it is desired to increase the energy of the hammer, by making it give blows even more powerful than those due to the highest fall of the hammer by gravity alone, the following simple but effective arrangement is brought into action. This contrivance consists in making the top of the cylinder quite steam and air tight, so that when the piston passes beyond the holes o o o o fig. 969, the old steam or air which is then pent up in the chamber Z Z above the piston, may obtain a reviving energy by the compression it receives from the upward motion of the piston, and this compression is wholly returned in the condition of elastic recoil of the most perfect kind, which recoil added to the simple gravity of the hammer vastly augments the rapidity and intensity of the blows. As soon as the piston re-passes the holes o o o o the old steam or air re-enters with perfect freedom, so as to offer no resistance to the fall of the hammer."

Fig. 968.

Fig. 969.

"It may be well to notice in conclusion, the peculiar, elastic, yet firm manner in which the connection between the piston rod and hammer block is made; this being one of the most important details in the whole arrangement, and without which this invention would have possessed but little practical utility. It will be seen in the enlarged section, fig. 969, that the piston rod has a large end F, forged to it, this goes down into a well inside the hammer block, and rests on several pieces of hard wood placed at W, one or two rings of the same material being placed above the part F, the whole being keyed hard down by two taper keys XX, which are driven in over the wood rings through the body of the hammer; these cross keys retain all the parts firmly together."

"This attachment while it effectually unites the piston rod and hammer, at the same time presents such an elastic or yielding medium, as to remove all risk of destructive action, which would be otherwise certain to occur, if any hard unyielding substance were placed between the anvil and hammer, or that these two parts were allowed accidentally to come in violent contact; no such concussion can now injuriously affect the piston and hammer. A close resemblance will be observed in this arrangement to that of the cartilage in the joints of animals between bone and bone."

The author of this volume has to add, that several of these steam hammers have been erected in our Government Dock Yards, and at the works of various engineers; sometimes they have flat-faced hammers and anvils for general purposes; at other times semicircular tools for swaging round shafts, and in this case peculiar advantages arises from the steam cushion, which prevents the approach of the tools bey one one precise distance, so that the shaft is made of uniform diameter throughout.

The steam hammer has also been employed in manufacturing large copper pans, into the central parts of which the convex hammer then dips with unerring precision, and any particular measure of force.

The largest of the steam hammers as yet made, has been erected in the works of Sir John Quest, Bart., Dowlais, South Wales, for the manufacture of wrought iron, and in this machine the hammer weighs 6 tons, it can be raised 7 feet, and its face measures 4 feet by 2 feet, so as to consolidate at one action, the entire mass of the blooms or uses for making railway bars, as the hammer face includes the whole surface of the bloom at every blow; the bed or anvil, perhaps the largest iron casting in the world, weighs 36 tons, and was cast in one mass from the united contents of four great furnaces.