Many establishments, and especially those of Haine-Saint Pierre, of Couillet, and of Seriang, in Belgium, and of Quillacq, at Anzin, have produced hoisting apparatus of this type which appear to leave little to be desired. Such machines are made either vertical or horizontal. In the former the winding reels are raised high in the air, and the only advantage appears to be that the inclination of the cable is lessened, so that the angle it makes with the surface of the sheave is increased. A disadvantage is the instability of the machine, owing to the little breadth of foundation, and to its great height. The horizontal engines are much more firm and substantial.

The accompanying illustration, printed upon a separate sheet and inserted, (page 584 A,) represents an engine of Quillacq's construction of the vertical type. This figure is reduced by Bien's photo-relief process from one of the beautifully engraved plates in Burat's Atlas. It does not require much explanation. One cylinder is shown in section with the piston at the lower end. The brake-wheel is between the two bobbins. The engineer stands upon an elevated platform on a level with the bobThree inches and bin-shaft, and controls the valves by means of levers. three-eighths of an inch upon this reduced drawing representsa distance of about five metres.

In all of these modern engines a very great improvement has been made by the addition of a powerful brake, worked by steam. Instead of the attendant exerting a large part of his strength upon the lever of a brake, it is now only necessary for him to open a valve by a hand lever, and thus admit steam to one side of a piston in a short cylinder, and the brake is instantly applied with greater force than a man could possibly exert. For such powerful engines as are now in use, and worked as they are at a high rate of speed, a brake of this kind is indispensable. Mr. Quillacq, constructing mechanical engineer at Anzin, appears to have been a pioneer in the construction of large direct-acting double hoisting engines. He published a description of one of these engines in 1859.*

The cylinders were each 0.600 in diameter, and the pistons had a stroke of 1.800; bobbin-shaft 3m.400 long and 0.290 in diameter; two bobbins 6m.500 in diameter; Stephenson slide motion; a steam brake, with the cylinder 0m.350 in diameter, drawing the two brakes of wood powerfully upon the periphery of a wheel 3m.300 in diameter. This machine was provided with signal indicators, and apparatus for arresting the motion of the engines and cages after the cages passed a certain point above the mouth of the shaft. The whole machine, with feed-pumps and fixtures, weighed 42,000 kilogrammes and cost less than 40,000 francs.

The same constructor exhibited a very beautiful hoisting apparatus at the Paris Exposition in 1867. It was a double engine of about 200 horse-power. The cylinders were vertical and connected directly with the bobbin-shaft, supported high in the air above the engines. Cylinders about 3 feet in diameter and 6 feet stroke. Link motion upon both. Bobbins for flat wire or hemp cable, and 22 feet in diameter. Steam brake, signal indicators, and apparatus for preventing overwinding were all included in this beautiful machine, for 38,000 francs. It appears from a bulletin that from 1856 to March, 1867, inclusive, the firm had supplied 67 machines of 7,012 horse-power in the aggregate, varying from 6 to 500 horse-power, the latter for pumping.

In a machine exhibited by A. Audry, engineer of the establishment of Mr. F. Dorzee, near Mons, the bobbin-shaft is placed below on a

# Annales des Mines.

level with the floor, and the cylinders rise vertically above it and act downward, instead of upward, as in the engine by Quillacq. The cylinders of this machine are 0.90 in diameter and the stroke 1m.40. Five machines have been made upon this model at different times from 1853 to 1867, varying in capacity from 80 to 150 horse-power.

A very beautiful machine of the direct-acting horizontal type was exhibited at Paris in 1867, by the establishment of M. M. Schneider & Co., of Creuzot. Its strength, proportions, and convenient arrangement of the various parts were admirable. The cylinders, 2m long and 0.550 in diameter, are placed 5.60 apart, from centre to centre. The rods are connected directly with cranks of 1m, placed at right angles upon the opposite ends of a main shaft, 0m.3 in diameter, which carries the two bobbins and the friction-wheel, to which the brakes are applied by means of steam, acting upon a piston in a small cylinder below the floor of the engine-room. The diameter of this wheel is 3m, and the length of each of the two wooden blocks which bear upon its periphery is 1m.2. The diameter of the drum of the bobbins is 2m.04, and total diameter along the arms is about 5m.5. The arms of the bobbins are of wood, and the extremities are not connected by segments, as in many of the Belgian and French machines. The length of the lever controlling the brakes is 1.9, the diameter of the cylinder 0.34, the length 0m.47.

The engineer stands midway between the forward ends of the cylinders, with both the bobbins in full view, and by means of conveniently placed levers and hand-wheels controls the movements of the engine and the operation of the steam-brake.

The details of construction of a portion of this engine are shown by the accompanying figure, reduced by the photo-relief process from the larger working drawings published in the Portefeuille des Ingénieurs, by the Messrs. Armengaud. The figure gives a longitudinal elevation of the bobbin, the brake-wheel, and brakes, together with the steam cylinder for operating the brake, and the levers by which the engineer controls the movements of the engine. The cylinders of the horizontal engines and their valves are not shown. B is the bobbin-shaft, carrying the bobbin with wooden spokes D D D and a cast-iron brake-wheel P P. The spokes, eight in number, are not united by segmental rims at their extremities, as in some machines, but are disconnected, the cable winding truly between the two opposite sets of spokes without catching upon their ends. These spokes are firmly bolted by their inner ends to a cast-iron socket plate, 2m.040 in diameter. This plate and the brakewheel P P are securely keyed to the shaft B. An arm, K, 1.90 in length, works loosely upon the shaft B, and by means of the connecting rods J J controls the brake pieces I I, faced with blocks of wood 1m.20 long, which fit into the hollow face of the brake-wheel P P. The brake-pieces, as will be seen, are supported in an upright position 3m.230 apart by the prolongation of their frames to the foundation below, to which they are united by hinge joints. The undue separation of these brake-pieces is prevented by set screws placed behind each, and their approximation and pressure upon the brake-wheel is controlled by means of the rod K, extending from the end of the arm K to the steam cylinder M. By means of the hand-lever O N steam can be instantly admitted to one side or the other of the piston in M, and thus operate the brakes with great force.

The engineer stands upon a platform just above the steam cylinder M, and controls the link-motion by means of the horizontal hand-wheel R. The dimensions and distances of the most important parts are indicated upon the figure in metres and in fractions of a metre.

At the mines of Sainte-Barbe, at Bezenet, the extraction from a depth of 161m to 185m is effected by a double horizontal engine, the two cylinders being connected directly with the bobbin-shaft. The pistons are Om.7 in diameter, and 1m.9 stroke. The drum or center of the bobbins is 3m.5 in diameter, and the minimum radius of winding space is therefore 1.75 for one of the bobbins, and greater for the other, which winds from the greatest depth. The brake is controlled by a separate steamcylinder. A contrivance for preventing accidents in case of over-winding closes the throttle-valve of the engine and puts on the steam-brake. This apparatus once prevented a very serious accident, by arresting the cage before it reached the sheaves.

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The cages weigh 1,900 kilogrammes, (1,600k iron, and 300 of wood,) and are made to receive six cars. Four sheet-iron cars weigh, when empty, 960 kilogrammes, and contain 20 hectolitres of coal, weighing 1,600 kilogrammes. The dead weight is therefore 1,900 + 960 2,860 kilogrammes. In ordinary working the time of ascension of the cage and load is 27 seconds. The landing and returning the cars require a mean of 18 seconds; total time, 45 seconds. Practically, they take out four cars a minute, or 240 cars per hour, and 2,400 in ten hours of effective work. Experience has shown that they can extract regularly 2,000 cars, containing 10,000 hectolitres, in ten hours. The two cables are adjusted to hoist from two levels, 24m apart. The drainage is effected with a single trip, and occupies only a part of the night. The quantity of water extracted varies between 6,000 and 10,000 hectolitres. The cables are 23 centimetres wide and 42 millimetres thick, made of iron wire covered with hemp.*

As an example of the dimensions and cost of modern hoisting engines in Saxony, the following from the notes of W. Fairley, mining engineer and surveyor, is interesting: The mine is at Zwickau, the Brückenberg colliery, 444 English fathoms in depth. The shaft is rectangular in section, 28 feet long by 8 feet broad; one-half of it is used for winding with two cages, the other half for a ladder-shaft and return air. The ventilation is effected by a Guibal's ventilator, measuring 7m by 3m, and driven by a 50-horse engine. The hoisting works consist of a pair of horizontal engines, built at the Wilhelm's Hütte, Sprottan, Schleswig, at a cost of £2,850. The cylinders are 42 inches diameter, stroke 8 feet, winding drum for flat ropes 12 feet diameter, ropes tapered. The time required for hoisting from the 444 fathom level is two and a half minutes, a speed of about 20 feet, on an average, per second. The cage carries two wagons of 10 hundred-weight side by side, and is furnished with a safety apparatus for its arrest in case of the breakage of the rope.

GENERAL OBSERVATIONS UPON HOISTING ENGINES.

In all these engines for collieries, where coal is so abundant and cheap, very little attention has been given to the question of economy of fuel, a very important one for regions like that of the Comstock, dependent upon wood brought from a distance at considerable expense. Condensing engines are too complex for hoisting purposes, where it is so often necessary to reverse the motion; and the only direction in which it appears possible to effect a great saving of steam is in working it expansively as much as possible by the use of suitable cut-off valves. The Exposition of 1867 contained a double engine on Woolf's plan, and consequently with four cylinders, which could be used advantageously as a

* From data supplied by MM. Lan and Baure to Professor Burat, 1867.