ClipArt ETC
"Heathen Deities: Vesta"-Willson, 1859.

Vesta

"Heathen Deities: Vesta"-Willson, 1859.

"Heathen Deities: Vulcan"-Willson, 1859.

Vulcan

"Heathen Deities: Vulcan"-Willson, 1859.

"The whole length of the tube of the wheel barometer, from C to A, is 34 or 35 inches, and it is filled with mercury, as usual. The mercury rises in the short leg to the point a, where there is a small piece of glass floating on its surface, to which there is attached a silk string, passing over the pulley p. To the axis of the pulley is fixed an index, or hand, and behind this is a graduated circle, as seen in the figure. It is obvious, that a very slight variation in the height of the mercury at o, will be indicated by a considerable motion of the index, and thus changes in the weight of the atmosphere, hardly perceptible by the common barometer, will become quite apparent by this." —Comstock, 1850

Wheel Barometer

"The whole length of the tube of the wheel barometer, from C to A, is 34 or 35 inches, and it is filled…

"As the mercury rises and lowers in the barometer, the float F turns the index, I. Index I points to the correct reading on the graduated scale S." —Quackenbos 1859

Wheel Barometer

"As the mercury rises and lowers in the barometer, the float F turns the index, I. Index I points to…

The wheel barometer consists of a siphon barometer, the two branches of which have usually the same diameter.

Wheel Barometer

The wheel barometer consists of a siphon barometer, the two branches of which have usually the same…

"Rotation of a Wheel. The same force which throws the wire away from the mercury, will cause the rotation of a spur-wheel. For this purpose the conducting wire, instead of being suspended, as in the former experiment, must be fixed firmly to the arm. A support for the axis of the wheel may be made by soldering a short piece to the side of the conducting wire, so as to make the form of a fork, the lower end of which must be flattened with a hammer, and pierced with fine orifices, o recieve the ends of the axis." —Comstock, 1850

Wheel Rotation

"Rotation of a Wheel. The same force which throws the wire away from the mercury, will cause the rotation…

"Vibration of a wire. A conducting copper wire, w, is suspended by a loop from a hook of the same metal, which passes through the arm of metal or wood, as seen in the cut. The upper end of the hook terminates in the cup P, to contain mercury. The lower end of the copper wire just touched the mercury, Q, contained in a little trough about an inch long, formed in the wood on which the horseshoe magnet, M, is laid, the mercury being equally distant from the two poles. The cup, N, has a stem of wire which passes through the wood of the platform into the mercury, this end of the wire being tinned, or amalgamated, so as to form a perfect contact." —Comstock, 1850

Wire Vibration

"Vibration of a wire. A conducting copper wire, w, is suspended by a loop from a hook of the same metal,…