Photocells for Laboratory Use

Cells having various types of composite coatings have been prepared. Particular attention has been given to better insulation and greater stability than is found in commercial cells

Operating Characteristics of Vapor-Type Vacuum Pumps

Pumps using mercury, n-butyl phthalate, and Apiezon oil have been tested for effectiveness against various fore pressures. Special designs have been worked out for use with Apiezon oil

A Gas-Type X-Ray Tube

The tube is, in general, of the Wyckoff type but the design has been re-worked for the purpose of better adaptation to the particular problem in hand. Simplification of machine work and utilization of standard parts have also received attention. The tube is being used by John W. Gowen for irradiating biological materials

A Lenard Ray Tube

The tube is constructed from materials readily available in the average laboratory shop. It is operated by a standard 100 kilovolt X-ray transformer

Some Effects Associated with Negative Corona Onset

Using concentric cylinder electrodes, observations were made on negative corona in hydrogen, argon, and nitrogen at pressures between 1 and 10 cm. of mercury. Positive ions produced by X-rays passing through argon in the corona chamber produced no measurable secondary effects at potentials below onset. Currents maintained by photo emission from the cathode became unstable at a potential near but definitely below onset

Fundamentals of X-Ray

X-rays were first detected in the year of 1895 by the German physicist, William Conrad Roentgen. The discovery occurred during a systematic search for radiation capable of penetrating materials opaque to ordinary light

A New Vaccum Type Mercury Still

The still consists of a compact single unit of Pyrex glass embodying a boiler, a water cooled condenser, and a receiver. Mercury can be poured from the receiver as required without disturbing the contents of the boiler

A Voltage Stabilization Device for Rectified A.C. Power Sources (Abstract)

The device is applicable to situations where currents of several milliamperes are required, as in the operation of low voltage X-ray tubes. With variation in line voltage not exceeding two per cent, fluctuations in output voltage, including ripple, are held within one-tenth per cent

Characteristics of Mercury Vapor Pumps

Curves showing relation between fore pressure and flow of mercury vapor required to produce a definite degree of exhaustion have been obtained for a mercury vapor pump. The pump is built according to definite specifications. Its general use will be discussed