Meteorological observations at the foreign and colonial stations of the Royal Engineers and the Army Medical Department, 1852-1886.

  • Great Britain. Meteorological Office.
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: Meteorological observations at the foreign and colonial stations of the Royal Engineers and the Army Medical Department, 1852-1886. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    realised, and at several stations observations were taken at nigbt (9.30 p.m. and 3.30 a.m.), and on additional “ Term Days At one of these stations—Mauritius—the series of night observations extended over nine years, and was so full and complete that it has been deemed well to publish the data with the day readings. There is, however, no information for the period from April 1862 (when the observing duty was taken over by the Army Medical Department) to December 1863. No data were published for this period, and it is found that the original schedules of observations have been destroyed. For the two following years, 1864, 1865, only the printed abstracts exist, the sheets for these years having also been destroyed. In consequence it will be found that the tables for the years in question (1864, 1865), are not in identically the same form as those for the other years, the pressures and tempe- ratures, for instance, being the means of the readings at 9 a.m. and 3 p.m., instead of the readings at the separate hours. For the same reason it has not been possible to verify, by reference to the observer’s figures, doubtful values in the results for these years. The changes in method between the Royal Engineers and the Army Medical Department were but slight, the most important being a difference of 30 minutes in the times of observing (the hours for the Royal Engineers being 9.30 a.m. and 3.30 p.m., while the Army Medical Department observed at 9 a.m. and 3 p.m.), and the dis- continuance of the “ Term-day ” observations. In other respects the two series are practically identical. The observations having been already prepared for publication, as stated above, it has not been deemed necessary as a general rule, to repeat the computations involved in the returns. In those cases, however, where the reduction or discussion appeared to be faulty, the working has been checked in the Meteorological Office. The wlole of the figures have been carefully read over with the original documents, and, in addition, much time has been spent upon a careful and systematic revision of the observations, which has led to the detection of many errors. In many instances the observations are not complete. At the Royal Engineer stations it seems to have been allowed to omit the readings on Sundays and public holidays, and this rule or permission was taken advantage of in many cases, though not in all. In addition there are the usual gaps owing to illness, absence of the observer, breakage of instruments, &c., &c. In all cases where the means are based on an incomplete series the fact is stated, and the number of missing observations is shown by small figures at the side of the readings. These incomplete means, however, have been used without question in obtaining the annual values. It should further be noted that the mean temperature, is taken to be the mean of the maxima and minima of those days only on which they have both been observed. Thus, if the maxima for a month are complete, but the minima on four days are missing, the maxima for those days have been omitted also, when obtaining the mean maximum to combine with the mean minimum. The mean temperature in such a case would therefore be based on observations for 27 days only. The monthly sums and means have been checked in a large number of cases, while the yearly totals and averages for all the stations have been obtained in the Meteoro- logical Office.