 | Frederick Walter Simms - 1845 - 184 pages
...undefined. To correct this error, first adjust the eye-glass, by means of the moveable eye-glass tube, till you can perceive the cross wire clearly defined,...the telescope, until you obtain the proper focus, according to the distance of the object, you are enabled at once to see clearly the object, and the... | |
 | Henry James Castle - Surveying - 1847 - 454 pages
...and distinct. If they are not, first adjust the eye-glass, by means of the moveable eye-glass tube, till you can perceive the cross wire clearly defined,...the telescope, until you obtain the proper focus, according to the distance of the object, you are enabled at once to see the object distinctly, as well... | |
 | John Fry Heather - 1849 - 202 pages
...undefined. To correct this error, first adjust the eye-piece, by means of the moveable eye-piece tube, till you can perceive the cross wire clearly defined,...white object. Then by moving the milled-head screw A, at the side of the telescope, the internal tube a is thrust outwards or drawn inwards, until you... | |
 | John Fry Heather - Astronomical instruments - 1851 - 208 pages
...undefined. To correct this error, first adjust the eye-piece, by means of the rnoveable eye-piece tube, till you can perceive the cross wire clearly defined,...marked against any white object. Then by moving the milled-headed screw A, at the side of the telescope, the internal tube a is thrust outwards or drawn... | |
 | Sir Henry Edward Landor Thuillier - Surveying - 1851 - 826 pages
...adjust the eye-piece, by means of the movable eye-piece tube, till you can perceive the cross-wire clearly defined, and sharply marked against any white object Then by moving the milled head screw A, at the side of the telescope, the internal tube a is thrust outwards or drawn... | |
 | John Fry Heather - Angles (Geometry) - 1859 - 198 pages
...undefined. To correct this error, first adjust the eye-piece, by means of the moveable eye-piece tube, till you can perceive the cross wire clearly defined,...marked against any white object. Then by moving the milled-headed screw A, at the side of the telescope, the internal tube a is thrust outwards or drawn... | |
 | John Fry Heather - Mathematical instruments - 1866 - 228 pages
...undefined. To correct this error, first adjust the eye-piece, by means of the moveable eye-piece tube, till you can perceive the cross wire clearly defined,...marked against any white object. Then by moving the milled-headed screw A, at the side of the telescope, the internal tube a is thrust outwards or drawn... | |
 | Spon E. & F.N., ltd - 1874 - 464 pages
...this error, first adjust the eye-piece, by means of the movable eye-piece tube, till the cross wire is clearly defined, and sharply marked against any white object. Then by moving the milled-headed screw at the side of the telescope, the internal tube is thrust outwards or drawn inwards,... | |
 | Edward Spon - Engineering - 1874 - 460 pages
...this error, first adjust the eye-piece, by means of the movable eye-piece tube, till the cross wire is clearly defined, and sharply marked against any white object. Then by moving the milled-headed screw at the side of the telescope, the internal tube is thrust outwards or drawn inwards,... | |
 | Edward Spon, Oliver Byrne, Ernest Spon, Francis N. Spon - Engineering - 1874 - 460 pages
...first adjust tho eye-piece, by means of the movable eye-piece tube, till the cross wire is cleurly defined, and sharply marked against any white object. Then by moving the milled-headed bcrew nt the side of the telescope, the internal tube is thrust outwards or drawn inward*,... | |
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The existence of parallax is determined by moving the eye about, when looking through the telescope, observing whether the cross wires change their position, and are flittering and undefined. To correct this error, first adjust the eye-piece, by means... 