OF OBSERVATIONS FOR TEMPERATURE. TEMPERATURE OF THE AIR IN SHADE OBSERVED ON BOARD THE YACHT Fox. March, 1859. 11 -21.06-21.00-21.57-19.45-14.79-11.89-12.03-13.77-18.43-19.22-19.52-20.66-17.78 Correction to refer mean to 24 observations = +0°.02. 12 RECORD AND REDUCTION TEMPERATURE OF THE AIR IN SHADE OBSERVED ON BOARD THE YACHT Fox. OF OBSERVATIONS FOR TEMPERATURE. TEMPERATURE OF THE AIR IN SHADE OBSERVED ON BOARD THE YACHT FOX. July, 1859. 13 Mean 72.0 94.2 +36.51+37.24+39 24+41.29 +42.90 +43.48+42.3441.98 +41 07+40.02 +38.56+36.98 +40.13 Correction to refer mean of 12 to mean of 24 observations August, 1859. -0°.01. TEMPERATURE OF THE AIR IN SHADE OBSERVED ON BOARD THE YACHT FOX. Notes to the preceding Abstract of the Temperature Record. July, 1857. The column headed "mean" contains the mean daily temperature derived from six equidistant observations; the figures in the next column of “deduced mean" were obtained as follows: Suppose the mean temperature of July 3d be required from the observations at 8 A. M. and 8 P. M., the observations at each of these hours in the full series were compared with their respective mean, as given in the preceding column; thus, from 23 values, we find the correction to the 8 A. M. reading, to obtain the mean reading of the day, +0°.8, and in a similar manner, for the 8 P. M. reading, +0°.2. Applying these corrections to 57°.0 and 57°.5 respectively, and taking the mean, we find for July 3d the mean temperature 57°.7. The following table contains these corrections to each observing hour in the month of July, in order to produce the mean of six readings a day, viz: The means require a further small correction to refer them to what they would be if hourly observations had been made. For this purpose, I have made use of the tables of hourly corrections for periodic variations for Boothia Felix and Drontheim, as given in the Smithsonian collection of meteorological and physical tables by A. Guyot, and also of a similar table given in the discussion of Dr. Kane's meteorological observations for Van Rensselaer Harbor, in Vol. XI. of the Smithsonian Contributions to Knowledge. For these localities, to which has been added Leith, we have, for the month of July, the correction to the mean of six observa tions at 4h, 8h, 12h, A. M. and P. M., to obtain the daily mean from twenty-four The resulting mean temperature for the month of July, in latitude 62° N. and longitude 39°.1 W. is, therefore, +45°.56 -0°.03 = +45°.53, as given in the general table of results. The means for the hours 4, 8, and 12, are derived from the observations between the 6th and the 31st, omitting those on the 19th, and taking 53° for the interpolated value at 41 A. M. on the 6th. For the sake of uniformity, the quantity +1°.26 has been added to each of these hourly means, so that the mean of all may again produce 45°.56. The correction to refer the mean from the observations at certain hours of the day to the mean derived from twenty-four readings a day, for the remaining months, has been deduced from the observations at Van Rensselaer Harbor and Boothia Felix. The following table contains these corrections: * Indicates that the weight 2 has been given to the correction derived from the Boothia Felix station, as being the nearer one. August, 1857. The two omissions on the 6th were supplied by 42° and 43°. September, 1857. The values for the 21st were interpolated as follows: 2 A. M. 12°.0, 6 A. M. 15°.2, and 10 A. M. 21°.2. From the observations between the 21st and 30th, we find that the mean of twelve observations a day is 0°.15 smaller than that derived from six observations a day; the second column of means between the 1st and 21st, therefore, is derived from the preceding column by subtracting 1 The interpolated value for 8 P. M. on the 21st is 38°.6. " " |