| Isaac Dalby - 1807 - 476 pages
...letiveen the sum of the two depressions and th-c contained arc SS (or angle C ) rx the refraction. TT 2 If one of the objects (B) instead of being depressed, is elevated, suppose to the point R; then the sum of the angles dAB -+- <fBA will be greater than the sum OAB -f OB A (or angle C) by... | |
| Thomas Keith - 1810 - 478 pages
...( / Bpf + / Asa) = / a sP + / £PS the sum of both the refractions. Hence the following ( Y) RULE. Subtract the sum of the two- depressions from the...arc, and half the remainder is the mean refraction. (Z) If one of the objects (A) instead of being depressed, be elevated, suppose to the point ey the... | |
| Thomas Keith - 1826 - 504 pages
...— (L Asa+ ¿BPÔ) = ¿.asv+ ¿ÔPS the sum of both the refractions. Hence the following (Y) RULE. Subtract the sum of the two depressions from the contained...arc, and half the remainder is the mean refraction. (Z) If one of the objects (A) instead of being depressed, be elevated, suppose to the point e, the... | |
| Thomas Keith - 1839 - 498 pages
...L OSP + L OPS) — ( l_ Asa + L ~BPb) =: L c — ( L Asa + L Bpfi). Hence the following (170) RULE. Subtract the sum of the two depressions from the contained...arc, and half the remainder is the mean refraction. (171) If one of the objects (A) instead of being depressed, be elevated, suppose to the point e, the... | |
| Edward Charles Frome - 1840 - 232 pages
...the angles 6AB, «BA, the sum of the two refractions ; hence, supposing half that sum to be the true refraction, we have the following rule when the objects...remainder is the mean refraction : — If one of the points B, instead of being depressed be elevated, suppose to the point g, the angle of elevation being... | |
| John Gregory - 1843 - 350 pages
...give the refraction. Hence the following rule, when both objects are reciprocally depressed. Deduct the sum of the two depressions from the contained...the remainder is the mean refraction. If one of the points, B, be elevated to the point g, instead of being depressed, then the rule is, subtract the depression... | |
| Basil Jackson - 1847 - 410 pages
...the difference between the sum of the two depressions and the contained arc, SS (or angle, C), is the refraction. If one of the objects (B), instead of...being depressed, is elevated, suppose to the point, R, then the sum of the angles, d AB + d BA, will be greater than the sum, OAB + OBA (or angle, C),... | |
| P. O'Shaughnessy (Civil engineer) - 1848 - 110 pages
...true refraction. Hence comes the following rule, when both objects are reciprocally depressed. Deduct the sum of the two depressions from the contained...arc, and half the remainder is the mean refraction. But if the point B, be elevated to the point X, instead of being depressed, then the rule is, substract... | |
| Edward Charles Frome - 1850 - 292 pages
...angles b AB, a .MA, the sum of the two refractions ; hence, supposing half that sum to be the true refraction, we have the following rule when the objects...remainder is the mean refraction : — If one of the points B, instead of being depressed, be elevated suppose to the point a, the angle of elevation being... | |
| Anthony Nesbit - 1859 - 494 pages
...ASa + Z. BP6) =(Z. OSP + Z. OPS) —(Z.ASa + Z.BPi)=ZC—(Z.ASa + Z.BP6). Hence the following RULE. Subtract the sum of the two depressions from the contained...remainder is the mean refraction. If one of the objects (A), instead of being depressed, be elevated, suppose to the point e, the Z of elevation being eSA... | |
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