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An illustration of a Roman galley from the Roman empire.

Roman Galley

An illustration of a Roman galley from the Roman empire.

A woman spinning cotton on a spinning jenny.

Spinning Jenny

A woman spinning cotton on a spinning jenny.

Sailboats docked at a harbor.

Harbor

Sailboats docked at a harbor.

A small boat; especially a small flat bottomed boat used in sea fisheries, in which to go out from a larger vessel to catch fish.

Dory

A small boat; especially a small flat bottomed boat used in sea fisheries, in which to go out from a…

Fishing from a Sail-boat.

Fishing

Fishing from a Sail-boat.

An optical instrument which the representatin of actual motion, as in leaping, walking, flying, etc.

Phanakistoscope

An optical instrument which the representatin of actual motion, as in leaping, walking, flying, etc.

A typical slave Dhow.

Slave Dhow

A typical slave Dhow.

Norse boat used as a habitation.

Norsemen

Norse boat used as a habitation.

A boat used by pilots for cruising off shore to meet incoming ships.

Coast Pilot

A boat used by pilots for cruising off shore to meet incoming ships.

A boat of Sumatra and the Malay archipelago, with from one to three masts, generally two, carrying square sails, and having much overhang or prejection at both stem and stern.

Pindjajap

A boat of Sumatra and the Malay archipelago, with from one to three masts, generally two, carrying square…

A boy playing with his toy ship.

Boy and Ship

A boy playing with his toy ship.

A lady in a boat.

Lady

A lady in a boat.

"The wheel and axle consists of two cylinders of different diameters, rigidly connected, so that they turn together about a common axis." — Hallock, 1905

Wheel and Axle

"The wheel and axle consists of two cylinders of different diameters, rigidly connected, so that they…

"The usual form of paddle-wheel, that is called the radial, in which the floats are fixed. It will be seen that a certain loss of power is involved, as the full force of the engine on the water is only experienced when the float is vertical, and as on entering and leaving the water the power is mainly devoted to respectively lifting and drawing down the vessel." — Chambers, 1881

Ordinary Paddle-wheel

"The usual form of paddle-wheel, that is called the radial, in which the floats are fixed. It will be…

"Elijah Galloway patented, in 1829, the Feathered Paddle-wheel, in which the floats are mounted on axes, and are connected by rods with a common center, which is made to revolve eccentrically to the axis of the paddle-wheel. By this method, the floats are kept, while immersed, at right angles to the surface of the water. So long as the water is smooth, and the immersion constant, the gain is great." — Chambers, 1881

Feathered Paddle-wheel

"Elijah Galloway patented, in 1829, the Feathered Paddle-wheel, in which the floats are mounted on axes,…

"The Romans, an essentially practical nation, largely improved on the plough, adding to it the coulter and mould-board, and occasionally attaching wheels to the beam to prevent the share from going too deep into the earth." — Chambers, 1881

Plough

"The Romans, an essentially practical nation, largely improved on the plough, adding to it the coulter…

"The plough is composed of two strong iron frames balanced upon four wheels, and crossing each other at their inner ends, thereby decreasing the length of the plough, and, as a matter of course, the breadth of the headland. The rames are raised and lowered in such a manner that the set of ploughs out of work is independent of, and has no tendency to weigh or raise out of the ground." — Chambers, 1881

Howard's Plough

"The plough is composed of two strong iron frames balanced upon four wheels, and crossing each other…

An agricultural tool used for flattening land and breaking up large pieces of dirt.

Press-Wheel Roller

An agricultural tool used for flattening land and breaking up large pieces of dirt.

The exterior wheel of the sun and planet motion of gears.

Planet Wheel

The exterior wheel of the sun and planet motion of gears.

A tool used to spin a piece of clay using converted motion from the users foot. Used mainly is making cylindrical objects.

Potters Wheel

A tool used to spin a piece of clay using converted motion from the users foot. Used mainly is making…

"The click barrel-ratchet R is set upon another larger ratchet-wheel, with its teeth pointing the opposite way, and its click rT is set in the clock-frame. That ratchet is connected with the great wheel by a spring ss' pressing against the two pins s in the ratchet and s' in the wheel. When you wind up the weight, the click Tr prevents the ratchet from turning back or to the right; and as the spring ss' is kept by the weight in a state of tension equivalent to the weight itself it will drive the wheel to the left for a short distance, when its end s is held fast, with the same force as if that end was pulled forward by the weight; and as the great wheel has to move very little during the short time the clock is winding, the spring will keep the clock going long enough." — Encyclopedia Britanica, 1893

Harrison's Going-Ratchet

"The click barrel-ratchet R is set upon another larger ratchet-wheel, with its teeth pointing the opposite…

"A front view of a common English house clock with the face taken off, showing the repeating or rack striking movement. Here, M is the hourwheel on the pipeof which the minute-hand is set, N the reversed hour-wheel, and n its pinion, driving the 12-hour wheel H, on whose socket is ficed what is called the snail Y, which belongs to the striking work exclusively. The hammer is raised by the eight pins in the rim of the second wheel in the striking train, in the manner which is obvious." — Encyclopedia Britanica, 1893

English House Clock

"A front view of a common English house clock with the face taken off, showing the repeating or rack…

"E represents the scape-wheel turning in a minute, and e its pinion, which is driven by the wheel D having a pinion d driven by the wheel C, which we may suppose to turn in an hour. The arbors of the scape-wheel and hour-wheel are distinct, their pivots-meeting in a bush fixed somewhere between the wheels. The pivots of the wheel, D are set in the frame AP, which rides on the arbors of the hour-wheel and scape-wheel, or on another short arbor between them. The hour-wheel also drives another wheel G, which again drives the pinion f on the arbor which carries the two arms f A, f B; and on the same arbor is set a fly with a ratchet, like a common striking fly, and the numbers of the teeth are so arranged that the fly will turn once for each turn of the scapewheel. The ends of the remontoire arms f A, f B are capable of alternately passing the notches cut half through the arbor of the scape-wheel, as those notches successively come into the proper position at the end of every half minute; as soon as that happens the-hour-wheel raises the movable wheel D and its frame through a small angle; but nevertheless, that wheel keeps pressing on the scape-wheel as if it were not moving, the point of contact of the wheel C and the pinion d being the fulcrum or center of motion of the level A d P." — Encyclopedia Britanica, 1893

Gravity Train Remontoire

"E represents the scape-wheel turning in a minute, and e its pinion, which is driven by the wheel D…

"The front view of a large quarter clock of Sir E. Beckett's design, with all the wheels on the great horizontal bed, a gravity escapemen, and a compensated pendulum. They are made in two sizes, one wih a great striking wheels 18 inches wide, and the other 14. The striking is done by cams cast on the great wheels, about 1.125 inch broad in the large-sized clocks, which are strong enough for an hour bell of thirty cwt., and corresponding quarters. Wire ropes are used, not only because they last longer, if kept greased, but because a sufficient number of coils will go on a barrel of less than half the length that would be required for hemp ropes of the same strength, without overlapping, which it is as well to avoid, if possible, though it is not so injurious to wire ropes as it is to hemp ones. by this means also the striking cams can be put on the great wheel, instead of the second wheel, which saves more in friction than could be imagined by any one who had not tried both. In clocks of the common construction two-thirds of the power is often wasted in friction and in the bad arrangement of the hammer work, and the clock is wearing itself out in doing nothing." — Encyclopedia Britanica, 1893

Quarter Clock

"The front view of a large quarter clock of Sir E. Beckett's design, with all the wheels on the great…

"This machine consists essentially of a horizontal piston and cylinder engine fixed upon a platform carried upon four wheels, which are coupled together by side rods, so that on motion being communicated by means of a mitre wheel in the hind axle, it can be moved forward by hand. On the forward end of the frame are two bosses forming the centres for a pair of bell cranks or bent levers places close to the ground, and facing in opposite directions, either one of which can be connected with the piston rod. The outer arm of each lever carries a square socket, into which is fixed the pick, which has two cutting heads, one placed a little in front of the other so as to cut to the whole depth at one operation." — Encyclopedia Britanica, 1893

Coal-cutting Machine

"This machine consists essentially of a horizontal piston and cylinder engine fixed upon a platform…

A utensil formerly in use for containing a small fixed amount of powder and introducing it into the pan of a gun.

Wheel Lock

A utensil formerly in use for containing a small fixed amount of powder and introducing it into the…

A proa boat with outrigger. Very swift and agile.

Proa

A proa boat with outrigger. Very swift and agile.

A small canoe shaped "boat" made of light materials and covered in reindeer skin. It is drawn by a single reindeer and it used to journeyover the snow in the winter. Usually about five feet long, one foot deep, and eighteen inches high. The rider sits up against the stern.

Lapland Pulk

A small canoe shaped "boat" made of light materials and covered in reindeer skin. It is drawn by a single…

A pulley with a convex rim, much used where various cases belts are in danger of slipping off.

Crown Pulley

A pulley with a convex rim, much used where various cases belts are in danger of slipping off.

A pulley with a sheave having its perimeter a rectangular or nearly rectangular groove. Used for transmitting power by ropes or bands.

Flat Rope Pulley

A pulley with a sheave having its perimeter a rectangular or nearly rectangular groove. Used for transmitting…

"A current is caused to pass from the mercury through C along the radius of the disc A through the field of magnetic force due to the horse-shoe magnet NO. The result is that the wheel rotates in the direction indicated by the arrow." — Encyclopedia Britannica, 1893

Barlow Apparatus

"A current is caused to pass from the mercury through C along the radius of the disc A through the field…

"Hearson's machine is cylindrical in form, and is surmounted by two turrets. Internally the cylinder is divided into two compartments by a transverse portion, one being occupied by a rotary blower, an apparatus similar in construction to the drum of a water-meter, and the other by an elevator or dipper wheel, the function of which is to raise gasolin into the blower chamber, where the gasoline must be maintained at a constant level." — Encyclopedia Britannica, 1893

Auto-Pneumatic Apparatus

"Hearson's machine is cylindrical in form, and is surmounted by two turrets. Internally the cylinder…

A broad flat bottom boat, used for transporting the products of India down the Ganges. It is from 40 to 65 feet long, lightly made, and capable of conveying heavy cargo.

Puteli

A broad flat bottom boat, used for transporting the products of India down the Ganges. It is from 40…

A boat used in emergency of a sinking ship.

Life Raft

A boat used in emergency of a sinking ship.

A wheel with pointed and anglar teeth, against which a ratchet abuts, used either for converting a reciprocating into a rotary motion or for admitting motion in one direction only.

Ratchet Wheel

A wheel with pointed and anglar teeth, against which a ratchet abuts, used either for converting a reciprocating…

"When a water fall ranges between 10 and 70 feet, and the water supply is from 3 to 25 cubic feet per second, it is possible to construct a bucket wheel on which the water acts chiefly by its weight. If the variation of the head-water level does not exceed 2 feet, an overshot wheel may be used. The water is then projected over the summit of the wheel, and falls in a parabolic path into the buckets. With greater variation of head-water level, a pitch-back or high breast wheel is better. The water falls over the top of a sliding sluice into the wheel, on the same side as the head race channel. By adjusting the height of the sluice, the requisite supply is given to the wheel in all positions of the head-water level. The wheel consists of a cast-iron or wrought-iron axle C supporting the weight of the wheel. To this are attached two sets of arms A of wood or iron, which support circular segmental plates termed shrouds B. A cylindrical sole plate dd extends between the shrouds on the inner side. The buckets are formed by wood planks or curved wrought-iron plates extending from shroud to shroud, the back of the buckets being formed by the sole plate." — Encyclopedia Britannica, 1893

Water Wheel

"When a water fall ranges between 10 and 70 feet, and the water supply is from 3 to 25 cubic feet per…

"Professor James Thomson's inward flow or vortex turbine has been selected as the type of reaction turbines. It is one of the best even in normal conditions of working, and the mode of regulation introduced is decidedly superior to that in most reaction turbines; it might almost be said to be the only mode of regulation which satisfies the conditions of efficient working, and it has been adopted in a modified form in the Leffel turbine, which is now largely used in america. The turbine has suction pipes, which permit the turbine to be placed at any height less than 30 feet above the tail-water level. The water enters the turbine by cast-iron supply pipes at A, and is discharged through two suction pipes S. The water on entering the case distributes itself through a rectangular supply chamber SC, from which it finds its way equally to the four guide-blade passages G. In these passages it acquires a velocity about equal to that due to half the fall, and is directed into the wheel at an angle of about 10 or 12 degrees with the tangent to its circumference. The wheel W receives the water in equal proportions from each guide-blade passage." — Encyclopedia Britannica, 1893

Reaction Turbine

"Professor James Thomson's inward flow or vortex turbine has been selected as the type of reaction turbines.…

"Professor James Thomson's inward flow or vortex turbine has been selected as the type of reaction turbines. It is one of the best even in normal conditions of working, and the mode of regulation introduced is decidedly superior to that in most reaction turbines; it might almost be said to be the only mode of regulation which satisfies the conditions of efficient working, and it has been adopted in a modified form in the Leffel turbine, which is now largely used in america. The turbine has suction pipes, which permit the turbine to be placed at any height less than 30 feet above the tail-water level. The water enters the turbine by cast-iron supply pipes at A, and is discharged through two suction pipes S. The water on entering the case distributes itself through a rectangular supply chamber SC, from which it finds its way equally to the four guide-blade passages G. In these passages it acquires a velocity about equal to that due to half the fall, and is directed into the wheel at an angle of about 10 or 12 degrees with the tangent to its circumference. The wheel W receives the water in equal proportions from each guide-blade passage." — Encyclopedia Britannica, 1893

Reaction Turbine

"Professor James Thomson's inward flow or vortex turbine has been selected as the type of reaction turbines.…

"Professor James Thomson's inward flow or vortex turbine has been selected as the type of reaction turbines. It is one of the best even in normal conditions of working, and the mode of regulation introduced is decidedly superior to that in most reaction turbines; it might almost be said to be the only mode of regulation which satisfies the conditions of efficient working, and it has been adopted in a modified form in the Leffel turbine, which is now largely used in america. The turbine has suction pipes, which permit the turbine to be placed at any height less than 30 feet above the tail-water level. The water enters the turbine by cast-iron supply pipes at A, and is discharged through two suction pipes S. The water on entering the case distributes itself through a rectangular supply chamber SC, from which it finds its way equally to the four guide-blade passages G. In these passages it acquires a velocity about equal to that due to half the fall, and is directed into the wheel at an angle of about 10 or 12 degrees with the tangent to its circumference. The wheel W receives the water in equal proportions from each guide-blade passage." — Encyclopedia Britannica, 1893

Reaction Turbine

"Professor James Thomson's inward flow or vortex turbine has been selected as the type of reaction turbines.…

"Professor James Thomson's inward flow or vortex turbine has been selected as the type of reaction turbines. It is one of the best even in normal conditions of working, and the mode of regulation introduced is decidedly superior to that in most reaction turbines; it might almost be said to be the only mode of regulation which satisfies the conditions of efficient working, and it has been adopted in a modified form in the Leffel turbine, which is now largely used in america. The turbine has suction pipes, which permit the turbine to be placed at any height less than 30 feet above the tail-water level. The water enters the turbine by cast-iron supply pipes at A, and is discharged through two suction pipes S. The water on entering the case distributes itself through a rectangular supply chamber SC, from which it finds its way equally to the four guide-blade passages G. In these passages it acquires a velocity about equal to that due to half the fall, and is directed into the wheel at an angle of about 10 or 12 degrees with the tangent to its circumference. The wheel W receives the water in equal proportions from each guide-blade passage." — Encyclopedia Britannica, 1893

Reaction Turbine

"Professor James Thomson's inward flow or vortex turbine has been selected as the type of reaction turbines.…

"The general sectionl elevation of a Girard turbine, in which the flow is axial. The water, admitted above a horizontal floor, passes down through the annular wheel containing the guide-blades, G, and thence into the revolving wheel WW. The revolving wheel is fixed to a hollow shaft suspended from the pivot p. The solid internal shaft ss is merely a fixed column supporting the pivot. The advantage of this is that the pivot is accessible for lubrication and adjustment. B is the mortise bevel wheel by which the power of the turbine is given off. The sluices are worked by the hand wheel h, which raises them successively, in a way to be described presently. a is the sluice rods." — Encyclopedia Britannica, 1893

Girard Turbine

"The general sectionl elevation of a Girard turbine, in which the flow is axial. The water, admitted…

"The sectional form of the guideblade chamber and the wheel and the curves of the wheel vanes and guideblades, when drawn on a plane development of the cylindrical section of the wheel; a, a, a are the sluices for cutting off the water; b, b, are apertures by which the entrance of exit of air is facilitated as the buckets empty and fill." — Encyclopedia Britannica, 1893

Guideblade Chamber

"The sectional form of the guideblade chamber and the wheel and the curves of the wheel vanes and guideblades,…

"The sectional form of the guideblade chamber and the wheel and the curves of the wheel vanes and guideblades, when drawn on a plane development of the cylindrical section of the wheel; a, a, a are the sluices for cutting off the water; b, b, are apertures by which the entrance of exit of air is facilitated as the buckets empty and fill." — Encyclopedia Britannica, 1893

Guideblade Chamber

"The sectional form of the guideblade chamber and the wheel and the curves of the wheel vanes and guideblades,…

"A centrifugal pump differing from an ordinary centrifugal pumps in one feature only. The water rises through a suction pipe S, which divides so as to enter the pump wheel at the center on each side. The pump disk or wheel is very similar to a turbine wheel. it is keyed on a shaft driven by a belt on a fast and loose pulley arrangement at P. The water rotating in the pump disk presses outwards, and if the speed is sufficient a continuous flow is maintained through the pump and into the discharge pipe D. The special feature in this pump is that the water, discharged by the pump disk with a whirling velocity of not inconsiderable magnitude, is allowed to continue rotation in a chamber somewhat larger than the pump. The use of this whirlpool chamber was first suggested by Professor James Thomson." — Encyclopedia Britannica, 1893

Centrifugal Pump

"A centrifugal pump differing from an ordinary centrifugal pumps in one feature only. The water rises…

"Road-racer. A full roadster would have the handles a little higher relatively to the saddle, and would be provided with mud-guards, free-wheel and sometimes a gear-case and variable speed gear." — The Encyclopedia Britannica, 1910

Road-Racer

"Road-racer. A full roadster would have the handles a little higher relatively to the saddle, and would…

"A ball-bearing hub with outward cups. The hub-shell H is turned out of mild steel, and the cups C are forced into the ends of the hub-shell and soldered thereto. A thin washer W is then spun into the end, for the purpose of retaining oil, and a thin internal tube T unites the two cups, and guides the oil fed in at the middle of the hub to the balls. The projecting flanges S are for the attachment of the tangent spokes used to build the hub into the wheel. The spindle A has the two cones screwed on it, one C, against the shoulder, the other C, adjustable. The-spindle ends are passed through the back-fork ends and are there adjusted in position by the chain-tension adjusters. After adjustments the nuts N clamp the spindle securely between the fork-ends. The chain-wheel or free-wheel clutch is screwed on the end of the hub-shell with a right-hand thread." — The Encyclopedia Britannica, 1910

Ball-bearing Hub

"A ball-bearing hub with outward cups. The hub-shell H is turned out of mild steel, and the cups C are…

"One end of the cup-adjusting hub, with inward bearings. The cones are formed of one piece with the spindles, and the adjusting cp C is screwed in the end of the hub shell, and locked in position by the screwed locking-ring R. The figure also illustrates a divided spindle for facilitating the removal of the tire for repair when required without disturbing the wheel, bearings, chain or gear-case. The chain side of the hub-spindle, not shown in the figure, is secured to the frame in the usual way; on the left side the spindle S projects very little beyond the adjusting cup. A distance washer W is placed between the end of the spindle S and the fork-end F. A detachable screw-pin, or the footstep, P, passes through the washer W, and is screwed into the end of the spindle S, the hexagod head of the detachable pin drawing all the parts securely together." — The Encyclopedia Britannica, 1910

Cup-adjusting Hub

"One end of the cup-adjusting hub, with inward bearings. The cones are formed of one piece with the…

"The usual form of crank-axle bearing which has inward-cups and is cup-adjusting. The end of the bracket is split and the cup after adjustment is clamped in position by the clamping screw S. The usual mode of fastening the cranks to the axle is by round cotters C with a flat surface at a slight angle to the axis, thus forming a wedge, which is driven in tight. The small end of the cotter projects through the crank, and is screwed and held in place by a nut. The chain-wheel at the crank-axis is usually detachable fastened to the right-hand crank." — The Encyclopedia Britannica, 1910

Crank-axle Bearing

"The usual form of crank-axle bearing which has inward-cups and is cup-adjusting. The end of the bracket…

"A genus of annual, subshrubby plants, order Solanaceae, with a wheel-shaped corolla, projecting and converging stamens, and a many-seeded berry. They are chiefly natives of the East and West Indies, China, Brazil, and Egypt, but have spread to various other tropical or subtropical countries, being cultivated for their fruit, which in some reaches the size of an orange, is fleshy and variously colored and contains a pungent principle, which is presented also and more largely in the seed." — Winston's Encyclopedia, 1919

Capsicum

"A genus of annual, subshrubby plants, order Solanaceae, with a wheel-shaped corolla, projecting and…

"A wheel driven by water shot over the top. The buckets of the wheel receive the water as nearly as possible at the top, and retain it until they approach the lowest point of the decent. The water acts principally by its gravity, though some effect is of course due to the velocity with which it arrives." — Winston's Encyclopedia, 1919

Water-wheel

"A wheel driven by water shot over the top. The buckets of the wheel receive the water as nearly as…

A wheel used to create energy by running water.

Water Wheel

A wheel used to create energy by running water.

A wheel used to create energy by running water.

Water Wheel

A wheel used to create energy by running water.

"The chain-pump consists of a tube or cylinder, the lower part of which is immersed in a well or reservoir, and the upper part enters the bottom of a cistern into which the water is to be raised. A chain is carried round a wheel at the top, and is furnished at equal distances with movable bottoms, which fit water-tight in the tube. As the wheel revolves, they successively enter the tube, and carry the water up before them, which is discharged into the cistern at the top of the tube." — Wells, 1857

Chain-Pump

"The chain-pump consists of a tube or cylinder, the lower part of which is immersed in a well or reservoir,…

"In the ordinary pattern of a lapidary's bench the handle turns in a horizontal plane, where W is the driving-wheel turned by the handle A, and working the pulley P by means of a strap. The pulley is fixed on a vertical spindle, which carries M the disk for slitting or the leaden lap for roughing or polishing. The upper end of this spindle is conical, and rotates in a socket drilled in a horizontal arm of iron which projects from a vertical wooden rod D. A block of wood C fits on to the end of an iron support termed the gim-peg or germ-peg. This support is used to steady the operator's arm when grinding the edges of small stones, and the wooden block, which is fixed by a wedge, is employed for cutting facets at any desired angle, the stone being cemented to the end of a stik S, which is fixed at the requisite angle in one of the holes or notches made in the sides of the socket C." —The Encyclopedia Britannica, 1910

Lapidary's Mill

"In the ordinary pattern of a lapidary's bench the handle turns in a horizontal plane, where W is the…

"Harness hides are washed by some means in pure water, the most convenient and generally adopted method being to place them in the dash wheel, in which they revolve and tumble about whilst fresh water is continually being poured on them within the revolving wheel." —The Encyclopedia Britannica, 1910

Dash Wheel

"Harness hides are washed by some means in pure water, the most convenient and generally adopted method…

A small row boat with row locks.

Row Boat

A small row boat with row locks.

A device used to attach an oar to a row boat.

Rowlock

A device used to attach an oar to a row boat.

"Atwood's Machine. This difficulty has however been overcome by a curious piece of machinery invented by Mr. Atwood. This consists of an upright pillar, with a wheel on the top. The weights A and B are of the same size and are made to balance each other, exactly, being connected by a thread passing over the wheel. The ring R admits the weight A, to fall through it in its passage to the stage S, on which it rests. The right and stage slide up and down, and are fastened by a thumb screw. The pillar is a graduated scale, and M is a small bent wire, weighing a quarter of an ounce, and longer than the diameter of the ring." —Comstock, 1850

Atwood's Machine

"Atwood's Machine. This difficulty has however been overcome by a curious piece of machinery invented…

"Windlass.—The common windlass for drawing water is another modification of the wheel and axle. The winch, or crank, by which it is turned, is moved around by the hand, and there is no difference in the principle, whether a whole wheel is turned, or a single spoke. The winch, therefore, answers to the wheel, while the rope is taken up, and the weight raised by the axle, as already described." —Comstock, 1850

Windlass

"Windlass.—The common windlass for drawing water is another modification of the wheel and axle.…

"System of Wheels.—As the wheel and axle is only a modification of the simple lever, so a system of wheels acting on each other, and transmitting the power to the resistance, is only another form of the compound lever. The first wheel a, by means of the teeth, or cogs, around its axle, moved the second wheel, b, with a force equal to that of a lever, the long arm of which extends from the center to the circumference of the wheel, where the power p is suspended, and the short arm from the same center to the ends of the cogs. The dotted line c, passing through the center of the wheel a, shows the position of the lever, as the wheel now stands." —Comstock, 1850

System of Wheels

"System of Wheels.—As the wheel and axle is only a modification of the simple lever, so a system…