 | Eneas Sweetland Dallas - 1870 - 532 pages
...opaque ; or by sidereflec tor, bull's-eye, &c. Remove A, and open the slit by means of the milled-head, H, at right angles to D D. When the slit is sufficiently...like an ordinary eye-piece, and any object can be focused in the usual way." Having focused the object, replace A, and gradually close the slit till... | |
 | Every boy - 1881 - 932 pages
...opaque, or by side reflector, bull'seye, &c. Kemovc A, and open the slit by means of the milled head, n, at right angles to D D. When the slit is sufficiently...gradually close the slit till a good spectrum is obtained. The spectrum will be much improved by throwing the object a little out of focus. Every part of the... | |
 | John Browning (F.R.A.S.) - 1882 - 108 pages
...reflector, bull's-eye, &c. Remove A, and open the slit by means of the milled head, H, at right angles to 1) D. When the slit is sufficiently open the rest of...gradually close the slit till a good spectrum is obtained. The spectrum will be much improved by throwing the object a little out of focus. Every part of the... | |
 | Jabez Hogg - 1886 - 850 pages
...open the slit by means of the milled-head, not shown in cut, but which is at right angles .to D i>. When the slit is sufficiently open the rest of the...gradually close the slit till a good spectrum is obtained. The spectrum will be much improved by throwing the object a little out of focus. Every part of the... | |
 | Robert Routledge - 1893 - 732 pages
...opaque, or by side reflector, bull's-eye, &c. Remove A, and open the slit by means of the milled head, H, at right angles to D D. When the slit is sufficiently...usual way. Having focussed the object, replace A, F shows the position of the field lens of the eye-piece. and gradually close the slit till a good spectrum... | |
 | Robert Routledge - 1896 - 780 pages
...opaque, or by side reflector, bull's-eye, &c. Remove A, and open the slit by means of the milled head, H, at right angles to D D. When the slit is sufficiently...gradually close the slit till a good spectrum is obtained. The spectrum will be much improved by throwing the object a little out of focus. Every part of the... | |
 | Jabez Hogg - 1898 - 780 pages
...opaque. Remove A, and open the slit by means of the milled-head, not shown in fignre, but which is at right angles to D D. When the slit is sufficiently open the rest of the apparatus acts as an ordinary eye-piece, and any object can be focussed in the usual way. Having focussed the object,... | |
 | Robert Routledge - 1903 - 882 pages
...opaque, or by side reflector, bull's-eye, &c. Remove A, and open the slit by means of the milled head, H, at right angles to D D. When the slit is sufficiently...any object can be focussed in the usual way. Having focusscd the object, replace A, and gradually close the slit till a good spectrum is obtained. The... | |
 | Isaac Ott - 1904 - 582 pages
...Illuminate with stage mirror if transparent. Kemove A and open the slit by means of the milled head H at right angles to D, D. When the slit is sufficiently...acts like an ordinary eyepiece, and any object can be focused in the usual way. Having focused the object, replace A and gradually close the slit till a... | |
 | Isaac Ott - 1907 - 852 pages
...Illuminate with stage mirror if transparent. Remove A and open the slit by means of the milled head // at right angles to D, D. When the slit is sufficiently...acts like an ordinary eyepiece, and any object can be focused in the usual way. Having focused the object, replace A and gradually close the slit till a... | |
| |
Having focussed the object, replace a, and gradually close the slit till a good spectrum is obtained. The spectrum will be much improved by throwing the object a little out of focus. Every part of the spectrum differs a little from adjacent parts in refrangibility,... 
