It is a simple instrument manufactured by the W. M. Welch Scientific Company of Chicago, Illinois c.a. 1922 for measuring "foot-candles" of illumination of any surface. A "foot-candle" is a unit of illumination on a surface that is everywhere one foot from a point source of one candle or equal to one lumen per square foot which is equal to one "lux". Argh...confusing? Forget it all and just read the position dial of your light meter.
It's called "Bohnenberger's Apparatus" [Johann von Bohnenberger--1817]. Gyroscopes were the product of Leon Foucault in 1852. This device antedates Foucault's by a few years and has the following text:
A compound lever.
This is a bench top instrument for the observation of the ionizing effects of radiation, high voltages, flames, etc....the Zeleny Electroscope ca. 1920.
It is an electromechanical devices that produce "static electricity" [Wimshurst Machine]--electricity at continuous direct current high voltage. Now rarely used except for physics's classroom demonstrations and monster creations.
This is the Pulfrich Pattern Refractometer. As a sale catalog states:
It is called "Hope's Apparatus" after the chemist Thomas Hope [1766-1844] [Edinburgh University]. The devise was an experiment to observe the contraction of water by heat at low temperatures. The large trough contained a freezing mixture and a thermometer was placed in the glass cylinder at the top and bottom [the openings can be seen at the left]. After some time it was observed that the denser water collected at the bottom at a temperature of 4° C and remained at that temperature illustrating the maximum density of water--a phenomenon observed by lake fish when the surface water froze.
The instrument is the Bourdon Tube illustrating the "aneroid barometer" to measure atmospheric pressure. Aneroid barometers have a sealed bellows that can expand and contract as a function of external pressure changes. This makes the instrument portable. It's non-portable counterpart is the "manometer" which relies on mercury and must be kept in a vertical position.
This is simply a transformer [step-up or step-down] from about 1914 and manufactured by C. H. Stoelting Company of Chicago, Illinois.
Known as a "slide-wire potentiometer" invented in 1841 by Johann Christian Poggendorff [1796-1877]. Poggendorff was also the editor of the "Annalen de Physik und Chemie" [1824 to 1876].
This is called the "Manometric Flame Apparatus" and was the standard for observing and measuring the wave shapes of sounds...sort of an early oscilloscope. It lost use when better and more accurate electrical devices came into vogue.
This apparatus was for the demonstration of mechanical oscillations. Interesting to note that the mirrored surfaces were of a complex coating [platinum chloride, lead borate, and lead oxide] to reduce double reflection. It was set into motion by hand spinning.
It is an adjustable capacitor apparatus from the collection at Cornell University. The brass plates are 57.5 inches in diameter with a 35 inch adjustment span on insulated threaded shafts. Even though this one is unmarked it does resemble the 1911 type manufactured by W.G. Pye & Co. [Cambridge, England]. Original cost was about $70 bucks. These old samples of physics apparatus sometimes reach the realm of art: Construction, casting, wood selection, metal lathe work.
It is "Hero's Fountain" and is named after Hero [Heron] who lived in Alexandria about 120 B.C. It essentially is a pneumatic device illustrating the use of "...both gravity and pressure to create a continuous fountain. Begin the fountain by pouring water into the funnel. Gravity pulls the water down the first tube and into the lower bottle. Increasing the amount of water in the lower bottle increases the air pressure in that bottle and in the second tube. The lower bottle is, in effect, "blowing" air into the upper bottle. This causes the air pressure to increase in the upper bottle, forcing water up the third tube. The water eventually pours out the top of the third tube, back into the funnel, and the cycle starts again. As long as you put in enough water, the Hero's Fountain will continue, using gravity and pressure, to operate until there is no more water in the upper bottle."
FOCUS X-RAY TUBE
This is a governor mechanism. In fact, the term "balls out" comes from this exact device. and back in the steam era it was necessary to maintain a constant engine speed invariant of load capacities on specific machinery. In silent cameras it enabled a skilled cameraman the ability to maintain a consistent film speed for smoother series of frame by frame exposure.