Crova's apparatus was designed for the purpose of representing vibratory movements on the screen, with 8 disks. Turning the crank past a vertical slit caused the disks to rotate, while a beam of light from the optical system impinged on the slit...
The Kinnersley's Thermometer was an apparatus designed to demonstrate the heating power of an electric spark by showing the expansion of air when an electric spark is passed through it. Physical Description: Glass tube with brass base and top,...
Electric discharges; X-ray tubes; Scientific apparatus and instruments
This instrument appears to be an early type of vacuum discharge tube or x-ray tube. The glass tube contains metal electrodes that have been sealed and from which the air has been removed by a vacuum system. Physical Description: Glass bulb with...
Thermodynamics--Experiments; Scientific apparatus and instruments
The brass ball will just pass through a brass ring when cold, but when the ball is heated in boiling water it expands so that it no longer passes through the ring. The ball and ring demonstration of heat expansion has been in use since the early...
Scientific apparatus and instruments; Optical instruments
The spherometer was used to measure the curvature of lenses. Physical Description: In mahogany case with sliding lid. Calibrated brass disk on three legs.
Electric discharges; Scientific apparatus and instruments
When connected to a power source, a bright electric spark would flash between the two ends of the two outer posts. The middle glass post is made of photo gray glass (yellow tinted glass), which would have glowed. This instrument is visible in early...
Scientific apparatus and instruments; Optical instruments
This device was used with a prism to demonstrate the seven colors of the specturm present in a beam of sunlight: red, orange, yellow, green, blue, indigo and violet. Physical Description: Seven movable mirrors, pivoted on brass holders, set in an...
Scientific apparatus and instruments; Induction coils
The Ruhmkorff induction coil consists of two separate coils of wire one inside the other wound around a cylinder with a central core of soft iron rods. When a current is passed through the first primary coil, current is induced in the secondary...
The Oersted Piezometer was used to determine the coefficient of the compressibility of liquids. Gases would have been pumped into the chamber through the funnel at the top. The pressure of the gases would have been measured via the water barometer...
This device is for measuring differences in temperature and was named for British natural philosopher John Leslie. It is considerably more sensitive than a standard thermometer. Physical Description: Wooden pedestal base, ivory-colored face,...
David Brewster, creator of Brewster's Law, patented this device in 1817. It consisted of a long, hollow tube containing two glass mirrors running along the length of the tube and separated from each other at an angle of 60 degrees. Where mirrors...
Scientific apparatus and instruments; Electric batteries
Grenet Batteries were single-element battery sources with flasks varying in size, from 1/3 liter to 3 liters. These batteries, when filled with an acid solution and placed in series, were a common source of electrical current prior to the...
Galvanometer; Scientific apparatus and instruments
A galvanometer is an instrument used to measure the presence, direction, and strength of small electric currents in a conductor. A magnetic needle is deflected by the presence of an electric current in a nearby conductor. The needle turns at right...
Scientific apparatus and instruments; Steam engines
The Eolypile (or aeolipile) is a metal sphere attached to a chariot half-filled with water and nested up to allow steam to build up. The steam is then allowed to escape in a jet making the chariot move. Physical Description: Brass 'cart' with three...
Scientific apparatus and instruments; Camera lucida;
An artist's aid for drawing, the camera Lucida was a portable device that was used to reproduce visual images on to paper. An adjustable prism mounted on the end of a supporting arm reflects the surrounding light and produces the image onto the...
Scientific apparatus and instruments; Simple machines; Archimedean screw
A simple mechanical device credited to Archimedes. When the lower end of the screw is placed in water, turning the device raises water to the top. This principle has various applications for drainage and irrigation, but the instrument can also be...
Scientific apparatus and instruments; Anamorphosis (visual perception)--Instruments
Described as one of many "Fine Optical Toys" in James W. Queen's Catalogue of Microscopes, Accessories and Sundries, 1890, the anamorphoscope mirror rectifies distorted drawings. Physical Description: Cylindrical mirror, black wooden top...
De Forest, Lee, 1873-1961; Postcards; San Jose (Calif.); Santa Clara County (Calif.)--History; Technology; Television receivers and reception;
Color postcard of Philco "Princess" Television, 1959. Back of card reads: "The 'Princess' was part of the Predicta line of Philco televisions produced in the late 1950's. The shape of the 'Princess' reflects the 'space age' design...
De Forest, Lee, 1873-1961; Postcards; Radio--Receivers and reception; San Jose (Calif.); Santa Clara County (Calif.)--History; Technology;
Color postcard of Gilfilan Brothers of Los Angeles cathedral style home broadcast radio receiver. Written on back of postcard, "In the early 1920's, 'wireless' devices used by amateurs were wires and circuitry attached to a wood base, called a...
