 | William Mudge, Isaac Dalby, Thomas Colby - 1801 - 690 pages
...angles 6AB, aBA, or the sum of the two refractions ; hence, if we suppose half that sum to be the mean refraction, we have the following rule, when the objects...the remainder is the mean refraction. If one of the objects (B) instead of being depressed, is elevated, suppose to the point G, the angle of elevation... | |
 | Thomas Keith - 1810 - 476 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
...their sum taken from the angle C,f (the contained arc of distance) will leave the angles 6AB, «BA, the sum of the two refractions ; hence, supposing...suppose to the point g, the angle of elevation being gA.D, then * " Trigonometrical Survey," vol. ip 175. See also, on this subject, Woodhouse's " Trigonometry,"... | |
 | John Gregory - 1843 - 352 pages
...give the refraction. Hence the following rule, when both objects are reciprocally depressed. Deduct the sum of the two depressions from the contained...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 from... | |
 | 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... | |
 | 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...the 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... | |
 | Canadian Society of Civil Engineers - 1890 - 832 pages
...their sum taken from the angle C (the contained arc of distance) will leave the angles b AB and a BA the sum of the two refractions ; hence supposing half...depressed : Subtract the sum of the two depressions rom the contained arc, and half the remainder it the mean refraction. the contained arc and the elivation... | |
 | Anthony Nesbit - 1859 - 482 pages
...ZBPS)-(Z ASa + ZBP6)=(Z OSP + L OPS) - ( L ASa + L BP6)= LC - ( L ASa + L BP4). Hence the following RULE. Subtract the sum of the two depressions from the contained arc, and half the remainder is'the mean refraction. If one of the objects (A), instead of being depressed, be elevated, suppose... | |
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AB, aBA, the sum of the two refractions ; hence, supposing half that sum to be the true refraction, we have the following rule when the objects are reciprocally depressed. Subtract the sum of the two depressions from the contained arc, and half the remainder... 