Practical observations on telescopes.

  • William Kitchiner
Date:
1815
Catalogue details

Licence: Public Domain Mark

Credit: Practical observations on telescopes. Source: Wellcome Collection.

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    be in a position of the greatest ease: no cramp or painful posture must distort the body, or irritate the mind; the whole powers of which must be concentrated in the eye: for such is the sympathy between the various organs of the human body, that we may as well attempt to think accurately on two subjects at the same time, as to use two senses at the same moment: — each must be used alone. As our immortal Shakspeare has observed of listening, with such profound attention, that “ each other sense was lost in that of hearing.” The smallest achromatic that can be used with effect for astronomical purposes, is the three and a half feet. These tele¬ scopes were originally furnished with three object-glasses of three inches and three- quarters diameter; but they are now usu¬ ally made with two object-glasses of two inches and three-quarters aperture. With this telescope all the principal and most interesting celestial phenomena may be pleasantly observed : and, indeed, if exqui¬ sitely perfect, it will discover the minutest
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