"A piston and rod shown with attached weight. The valve, A, can be opened and closed as needed so that the piston can be moved." —Hallock 1905

Piston and Rod

"A piston and rod shown with attached weight. The valve, A, can be opened and closed as needed so that…

"The piston rods are furnished with racks, or teeth, and are worked by the toothed wheel a, which is turned backwards and forwards, by the lever and handle b. The exhaustion pipe c, leads to the plate on which the receiver stants. The valves v, n, u, and m, all open upwards." —Comstock, 1850

Air Pump

"The piston rods are furnished with racks, or teeth, and are worked by the toothed wheel a, which is…

"According to the ancient authorities, it was made of bronze, and its form was oval, but with the two sides receding inward with an even curvature, and so as to make it broader at the ends than in the middle. The original ancile was said to have fallen from the skies in the time of Numa. To secure its preservation, Numa ordered eleven other shields to be made exactly like it. These twelve <em>ancilia</em> were kept in the temple of Mars Gradivus, and were taken from it only once a year, on the kalends of March. The feast of the god was then observed during several days; when the Salii, or priests of Mars, twelve in number, carried the sacred shields about the city, singing songs in praise of Mars, Numa, and Mamurius Veturius, who made the eleven. They at the same time performed a dance, in which they struck the shield with rods, so as to keep time with their voices and with the movements of the dance." &mdash; Anthon, 1891

Ancilia

"According to the ancient authorities, it was made of bronze, and its form was oval, but with the two…

Arc lighting, which used two carbon rods conducting electricity to produce light. -Atkinson 1903

Carbon Arc Lighting

Arc lighting, which used two carbon rods conducting electricity to produce light. -Atkinson 1903

"a, the osseous septum grooved for the passage of the cochlear nerve b, which terminates by a free end inside the chamber c, along the floor of which it lies for a short distance; d, d are the two layers of the membranous septum. Lying in contact with the end of the nerve is the enlarged extremity of a rod e, which is connected in a flail-like manner by the hinge f to another rod, which is fixed at g." &mdash; Chambers' Encyclopedia, 1875

Auditory Nerve

"a, the osseous septum grooved for the passage of the cochlear nerve b, which terminates by a free end…

"Cylinders showing piston in place and connected to crankshaft. Gasoline vapor is exploded in the cylinders. This pushes the piston down, and as the piston is connected to the crankshaft it starts the crankshaft turning. The piston and the rod that connect it to the crankshaft are just like the feet and limbs of any one riding a bicycle." -Bodmer, 1917

Building an Automobile, Step 03: Cylinders Showing Piston and Crankshaft

"Cylinders showing piston in place and connected to crankshaft. Gasoline vapor is exploded in the cylinders.…

"The gears or 'cogwheels' are for running the fan, the pump and other parts." -Bodmer, 1917

Building an Automobile, Step 04: Cogwheels

"The gears or 'cogwheels' are for running the fan, the pump and other parts." -Bodmer, 1917

"A cantilever is a beam, bar, rod, etc., fixed at one end and subjected to a transverse stress. It has a tendency to overthrow the wall or structure to which it is attached." &mdash; Hallock, 1905

Cantilever

"A cantilever is a beam, bar, rod, etc., fixed at one end and subjected to a transverse stress. It has…

"When the load is uniformly distributed on a cantilever of any cross-section, it will sustain a load twice as great as when the load is applied at one end." &mdash; Hallock, 1905

Cantilever

"When the load is uniformly distributed on a cantilever of any cross-section, it will sustain a load…

A rectangular cantilever with supports on the end and the load on the middle.

Cantilever

A rectangular cantilever with supports on the end and the load on the middle.

"When two bodies of equal weight are connected by a rod, the centre of gravity will lie in the middle of that rod. When two bodies of unequal weight are so connected, the centre of gravity will be nearer to the heavier one. These principles are illustrated [here], in which C represents the centre of gravity." &mdash;Quackenbos 1859

Center of Gravity of Rod with Weights

"When two bodies of equal weight are connected by a rod, the centre of gravity will lie in the middle…

A rod with a slender wire coiled loosely around it.

Coil around rod

A rod with a slender wire coiled loosely around it.

A sceptre from the seal of Edward the Confessor.

Sceptre of Edward the Confessor

A sceptre from the seal of Edward the Confessor.

"Gold leaf electroscope; it consists of two strips of gold foil suspended from a brass rod within a glass jar. Used to detect the presence and sign of an electric charge." -Hawkins, 1917

Gold Leaf Electroscope

"Gold leaf electroscope; it consists of two strips of gold foil suspended from a brass rod within a…

"Of all the contrivances for regulating the motion of machinery, this is said to be the most effectual. It will be readily understood by the following description. It consists of two heavy iron balls b, attached to the extremities of the two rods, b, e. These rods play on a joint at e, passing through a mortice in the vertical stem d, d. At f, these pieces are united, by joints to two short rods, f, h, which, at their upper ends, are again connected by joints at h, to a ring which slides upon the vertical stem d d." &mdash;Comstock, 1850

Governor

"Of all the contrivances for regulating the motion of machinery, this is said to be the most effectual.…

Gray & Davis starting motor with reduction gearing for open flywheel. 1-Motor Pinion; 2-Intermediate Gear; 5-Intermediate Shaft; 6-Sliding Pinion; 7-Shifter Fork; 8-Shifter Rod; 10-Clevis; 12-Switch Rod; 23, 24, and 25-Oilers; 26-Oil Plug.

Gray and Davis Motor

Gray & Davis starting motor with reduction gearing for open flywheel. 1-Motor Pinion; 2-Intermediate…

A steel rod being held horizontally by a pair of hands.

Hands with rod

A steel rod being held horizontally by a pair of hands.

Ancient household utensils from Pompeii

Household Utensils

Ancient household utensils from Pompeii

A pivoted joint in the nature of a hinge joint, whereby two thin flat strips may be so united that each edge will turn edgewise towards and from eachother.

Prop Joint

A pivoted joint in the nature of a hinge joint, whereby two thin flat strips may be so united that each…

An old fishing rod and lure.

Old Fishing Rod

An old fishing rod and lure.

"Its mechanism may be understood by the means of the subjoined figure, B represents the end of the beam, which is pulled downward, and pushed upward, by the motion of the piston-rod R P; the motion of B is in the direction of the dotted curve; that of R P is rectilinear." &mdash;Comstock, 1850

Parallel Motion

"Its mechanism may be understood by the means of the subjoined figure, B represents the end of the beam,…

A rod which connects a rotary with a reciprocating part, either for imparting motion to the latter or taking motion from it, as that which couples a crank with a saw gate, or a steam piston with its crank shaft.

Pitman

A rod which connects a rotary with a reciprocating part, either for imparting motion to the latter or…

"A proof-plane may be made by cementing a bronze cent or a disk of gilt paper to a thin insulating handle, as a glass tube or a vulcanite rod. Slide the disk of the proof-plane along the surface of the electrified body to be tested, and quickly bring it into contact with the knob of the gold-leaf electroscope, the leaves of which will diverge." &mdash; Avery, 1895

Hand with proof-plane

"A proof-plane may be made by cementing a bronze cent or a disk of gilt paper to a thin insulating handle,…

"Reversing rod inside hollow propeller shaft: by twisting the blades round, the motion of the boat is reversed without changing the rotation of the screw."&mdash;Finley, 1917

Reversible propeller

"Reversing rod inside hollow propeller shaft: by twisting the blades round, the motion of the boat is…

"Suppose the rod a, to be set with one half of its length below the surface of the water and the other half above it. The eye being placed in an oblique direction will see the lower end apparently at the point o, while the real termination of the rod would be at n; the refraction will therefore make the rod appear shorter by the distance from o to n, or one-fourth shorter than the part below the water really is." -Comstock 1850

Refraction, water

"Suppose the rod a, to be set with one half of its length below the surface of the water and the other…

Perpendicular section of mammalian retina. Labels: A, layer of rods and cones; B, outer nuclear layer; C, outer molecular layer; D, inner nuclear layer; E, inner molecular layer; F, ganglionic layer; G, stratum opticum; r, rods; c, cones, r.g, rod granules; c.g, cone granules; r.b, rod bipolars; c.b, cone bipolars; c.r, vontact of rod bipolars with the internal arborisation of cone bipolars; ar', internal arborisation of rod bipolars; c.n, centrifugal nerve fiber; h, horizontal cells; s.s, stratified spongioblasts; d.s, diffuse spongioblasts; s.g, stratified ganglion cell; M, sustentacular fiber of Muller.

Section of Retina

Perpendicular section of mammalian retina. Labels: A, layer of rods and cones; B, outer nuclear layer;…

&quot;A vertical rod, generally of iron, with a heavy metallic foot, and a number of metallic rings, of different sizes ... the whole serves to support a retort or other vessel, properly adjusted as to height, over a lamp-flame.&quot; -Whitney, 1911

Retort Stand

"A vertical rod, generally of iron, with a heavy metallic foot, and a number of metallic rings,…

A rod in a wire stirrup, suspended by a thread.

Rod in stirrup

A rod in a wire stirrup, suspended by a thread.

This illustrates how to determine the force required to turn a connecting rod of a steam engine.

Connecting Rod of a Steam Engine

This illustrates how to determine the force required to turn a connecting rod of a steam engine.

An illustration of a boring rod by using a hand cranked lathe. This device creates a cylinder with a hollow center from rods.

Hand Crank Lathe Boring Rod

An illustration of a boring rod by using a hand cranked lathe. This device creates a cylinder with a…

A mechanical boring rod machine to create a cylinder with a hollow center.

Mechanical Boring Rod

A mechanical boring rod machine to create a cylinder with a hollow center.

Steel rods connecting the pump inside well tubing down-hole to the pumping jack on the surface.

Sucker Rod

Steel rods connecting the pump inside well tubing down-hole to the pumping jack on the surface.

An ancient Greek sceptre from Tarentum.

Ancient Greek sceptre

An ancient Greek sceptre from Tarentum.

Gold and crystal sceptres from Mycan&aelig;.

Mycanæ:n sceptres

Gold and crystal sceptres from Mycanæ.

"Any rod, or bar, which is used in raising a weight, or surmounting a resistance, by being placed on a fulcrum, or prop, becomes a lever." -Comstock 1850

Simple Lever

"Any rod, or bar, which is used in raising a weight, or surmounting a resistance, by being placed on…

"Long rod-like form containing a spore (these are the so-called "Kopfchenbacterien" of German authors)." &mdash; The Encyclopedia Britannica, 1910

Spore

"Long rod-like form containing a spore (these are the so-called "Kopfchenbacterien" of German authors)."…

A hand with bar demonstrating the attractive properties of static electricity.

Demonstration of Static Electricity

A hand with bar demonstrating the attractive properties of static electricity.

A hand with a rod, demonstrating the attractive properties of static electricity.

Demonstration of Static Electricity

A hand with a rod, demonstrating the attractive properties of static electricity.

"The sweating blacksmith here is seen to stand / Beside his forge, with hammer in his hand, / And while the fiery sparks are flying far, / With might and main he strikes the red-hot bar." &mdash;Barber, 1857

Strike While the Iron is Hot

"The sweating blacksmith here is seen to stand / Beside his forge, with hammer in his hand, / And while…

The temple of Jupiter torus moulding is found in Rome, Italy. It is a design of a rod that is covered with foliage.

Temple of Jupiter Torus Moulding

The temple of Jupiter torus moulding is found in Rome, Italy. It is a design of a rod that is covered…