IT need not be said that in astronomical observation it is always desirable, to say the least of it, to have a tolerably correct estimate of the magnifying power actually in use. This has hitherto ...

Invented by an electrical engineer named Francis Cutler Ellis (1890-1957), the Ellis Micro-Dynameter promised to make the human body “function as a simple electrical cell and measure the current it ...

Francis Cutler Ellis, an engineer in Chicago, devised the Ellis Micro-Dynameter in the early 1930s. This device, it was said, would “make the human body function as a simple electrical cell and ...

THE letter from the Rev. T. W. Webb in your last number is a very tantalising letter. He tells us, and we could not wish to have a better authority, that a new dynameter has been invented by the Rev.