Lectures on Practical Astronomy and Astronomical Instruments (1879)
Challis, James Rev. · Deighton, Bell and Co. (Cambridge) · leaf 433
392 PRACTICAL ASTRONOMY. the parts of a Dollond’s Dynameter, the construction of which is very nearly the same as that of a Dynameter made by … Troughton and Simms, which I made use of for finding the magnifying powers of the various eye-pieces pertaining to the Telescopes of the Cambridge Observatory, and afterwards exhibited to my astronomical class. In the two Figures f is the circular micrometer-head divided on its rim into 100 equal…
Book · Astronomy
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