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 ...

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 ...

Object Details Description 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 ...

Micro-Dynameter Physical Description wood (overall material) metal (overall material) Measurements overall: 17 1/2 in x 16 1/4 in x 9 in; 44.45 cm x 41.275 cm x 22.86 cm place made United States: ...