This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1887 Excerpt: ...determinations of the latitude, by different methods and observers, substantially harmonize with the value 47."6 for the dome, or 48."4 for the almucantar pier. We have thus an independent test of the accuracy of the instrumental constants within 0."1 or 0."2. The fact is also demonstrated, that no cause of disturbance ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1887 Excerpt: ...determinations of the latitude, by different methods and observers, substantially harmonize with the value 47."6 for the dome, or 48."4 for the almucantar pier. We have thus an independent test of the accuracy of the instrumental constants within 0."1 or 0."2. The fact is also demonstrated, that no cause of disturbance of the direction of gravity indicated by the instrument could have existed on the nights in question which could affect the latitude 0."l. In other words, if there was such a disturbance, causing a deflection of the instrumental from the true zenith, it must have been so nearly east or west that the projection of the deflection upon the meridian was less than 0."1. Further, the mechanical tests by means of various spirit-levels, detailed in the succeeding chapter, show that the direction of gravity indicated by the almucantar coincides with that of the levels, and warrant the conclusion that there is no deviation in any direction so great as 0."1; thus, if existing, it is below the limit of measurement. These considerations, which seem to exhaust the rational instrumental sources of error pertaining to the almucantar, furnish a strong presumption that the origin of the observed difference in the clock corrections lies elsewhere. An enumeration of the possible sources of such an error in the meridian circle would include pivot irregularities, irregular curvature of the level tube or erroneous value of the level divisions, and disagreement between the horizontal collimation measured by the collimators and the astronomical collimation, --a disagreement which might be purely instrumental, or might partly arise from personal peculiarity in collimating, traces of which have been found by Dunkin among the observers ...
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Add this copy of Annals of the Astronomical Observatory of Harvard to cart. $41.63, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2018 by Palala Press.
Add this copy of Annals of the Astronomical Observatory of Harvard to cart. $49.33, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2011 by Nabu Press.
