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. 1876 Excerpt: ...and their sum are as follows:--The above corrections refer to the middle of each month, and by interpolation they were found for each day. Williamstown, Mass. Lat. 420 43'. Long. 730 13' W. of G. Alt. 721 feet. 23 years of observation; from 1816 to 1838, inclusive. Prof. C. Dewey and Prof. "E. Kellogg. MS. in Smithsonian Coll. Providenoe, Rhode Island. Lat. 41 50'. Long. 71 24' W. of G. Alt. 155 feet. 28 years of observation; Dec. 1831, to May, 1860, inclusive. Prof. A. Caswell, observer. Srrifhsonian Cont. to Knowl. Washington, 1860. Observing hours various, generally Qr, ', or 2,, ioa, from Oct. to March, inclusive, and 6m, '. or 2a, 'oft, in the remaining months. The tabular quantities are corrected for daily fluctuation. To correct the observed daily means resulting from three observations a day, taken at various hours, the following table was prepared and used:--The above corrections apply to the middle of each month, and were interpolated for every day. Observations at 3 P. M. for 2 years, at 9 P. M. for 10 years, and at 7 A. M., 2 and 9 P. M. for 9 years. Tabular numbers corrected for daily fluctuation. In computing the original table, the observations at 3 P. M. were used for two of the years, those at 9 P. M. for ten, and the daily means at 7 A. M., 2 and 9 P. M. for the remaining nine. When combine"! they afford a tolerable approximation to the true mean, as may be seen from the following statement, which shows the correction for daily fluctuation at 2 and 9 P. M. deduced from the observations of ten years of this series, from 1820 to 1829, inclusive, and the reduction from 2 P. M. to 3 P. M. from the Mohawk table of daily fluctuation:--The correction to mean of 7, 2, 9 is from the Mohawk table; now twice the correction 3 P. M. + ten tim...
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