| John F. Heather - 1849 - 208 pages
...those of the index glass very nearly. But what is of still more consequence, the error of the center is perfectly corrected by reading the three branches...as one hundred and fifty degrees, consequently the sun-s double altitude may be observed when his distance from the zenith is not less than fifteen degrees... | |
| Sir Henry Edward Landor Thuillier - 1851 - 826 pages
...observe forwards first, where the whole range is without interruption ; whereas, in that backwards, you will lose sight of the reflected image about that...onesixth part of their simple value. Moreover, angles maybe measured as far as one hundred and fifty degrees, consequently the sun's double altitude may... | |
| John Fry Heather - 1859 - 198 pages
...those of the index glass very nearly. But what is of still more consequence, the error of the center is perfectly corrected by reading the three branches...Moreover, angles may be measured as far as one hundred and fifiy degrees, consequently the sun's double altitude may be observed when his distance from the zenith... | |
| 1860 - 938 pages
...corrects the errors of the horizon glass, and those of the index glass very nearly. But what is of still more consequence, the error of the centre is perfectly...both ways, probably reduces the errors of dividing the one-sixth part of their simple value. Moreover, angles may be measured as far as one hundred and... | |
| John Fry Heather - 1866 - 228 pages
...those of the index glass very nearly. But what is of still more consequence, the error of the center is perfectly corrected by reading the three branches...both ways, probably reduces the errors of dividing to one-sixth'part of their simple value. Moreover, angles may be measured as far as one hundred and fifty... | |
| 1835 - 596 pages
...quantity. This also perfectly corrects the errors of the horizon- glass, and those of the index -glass very nearly. But what is still of more consequence,...value. Moreover, angles may be measured as far as 130 degrees, consequently the sun's double altitude may be observed when his distance from the zenith... | |
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