Astronomy with an opera-glass: a popular introduction to the study of the starry heavens with the simplest of optical instruments, with maps and directions to facilitate the recognition of the constellations and the principal stars visible to the naked eye; (1888)
Serviss, Garrett Putman, 1851-1929 · New York, London, D. Appleton and company · leaf 16
t gives a perfectlyround field. Some glasses have an arrangement for adjust-ing the distance between the barrels to suit the eyes of dif-ferent persons, and it would be well if all were made adjust-able in the same way. Dont buy a cheap glass, but dont waste your money onfancy mountings. What the… … A very Bad Field. 6 ASTRONOMY WITH AN OPERA-GLASS. strument, may generally be regarded as a guarantee of excel-lence. But the best test is that of actual performance. Ihave a field-glass which I found in a pawn-shop, that has nomakers name upon it, but in some respects is quite capableof bearing…
Astronomy
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