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... Elementary text book for young surveyors and levellers - Side 102av Henry James Castle - 1856 - 185 siderUten tilgangsbegrensning - Om denne boken
| Frederick Walter Simms - 1845 - 184 sider
...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 - 1847 - 454 sider
...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 sider
...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 - 1851 - 208 sider
...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 - 1851 - 826 sider
...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 - 1859 - 198 sider
...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 - 1866 - 228 sider
...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 sider
...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 - 1874 - 460 sider
...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 - 1874 - 460 sider
...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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