...be carried much farther, so as to reduce the usual length of refracting telescopes nearly one-half, without increasing the aberration in the first glass...slight movement of the fluid lens, as in the Gregorian reflectors by means of the small speculum. In the latter case the eye-piece is fixed, which may probably...

...be carried much farther, so as to reduce the usual length of refracting telescopes nearly one-half, without increasing the aberration in the first glass...slight movement of the fluid lens, as in the Gregorian reflectors by means of the small speculum. In the latter case the eye-piece is fixed, which may probably...

...be carried much farther, so as to reduce the usual length of refracting telescopes nearly one-half, without increasing the aberration in the first glass...slight movement of the fluid lens, as in the Gregorian reflectors, by means of the small speculum. In the latter case, the eye-piece is fixed, which may probably...

...be carried much farther, so as to reduce the usual length of refracting telescopes nearly one half without increasing the aberration in the first glass...telescope of the usual kind of the whole length. It should likewise be observed that the adjustment for focus may be made either in the usual way, or by a slight...

...be carried much farther, so as to reduce the usual length of refracting telescopes nearly one half without increasing the aberration in the first glass...telescope of the usual kind of the whole length. It should likewise be observed that the adjustment for focus may be made either in the usual way, or by a slight...

...reduce the usual length of refracting telescopes nearly one half, without increasing the aberration ш the first glass beyond the least that can possibly...telescope of the usual kind of the whole length. It should likewise be observed, that the adjustment for focus may be made either in the usual way or by a slight...