## On the potential difference that is needed for sparking in air, hydrogen, and CO2 at different pressures

The study of the nucleus would be greatly facilitated by the development of sources of high speed ions, particularly protons and helium ions, having kinetic energies in excess of 1,000,000 volt-electrons; for it appears that such swiftly moving particles are best suited to the task of nuclear excitation. The straightforward method of accelerating i...

Streams of fast electrons which can accumulate positive ions in sufficient quantity to have a linear density of positives about equal to the linear density of electrons, along the stream, become magnetically self-focussing when the current exceeds a value which can be calculated from the initial stream conditions. Focussing conditions obtain when b...

A new approach to the relativity theory, suggested by the theory of E. A. Milne, is developed. This approach, like Milne's, dispenses with the concepts of measuring rods of undefinable rigidity and clocks of undefinable periodicity. A new category of equivalent relatively accelerated reference systems with Euclidean geometry and constant light-velo...

The transformation for E and H between equivalent Euclidean reference systems with constant relative acceleration is obtained, and the necessary modification of the classical equation of motion of the electron is deduced.

Significant improvements of the apparatus for the multiple acceleration of light ions, now called the "cyclotron," have recently been made. The apparatus produces many microamperes of deuterons having energies up to 6.3 Mev and a few tenths of a microampere of 11 Mev doubly charged helium ions. The means of deflecting the high speed ions from the a...