DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.20140#0123
V. CALCULATION OF THE DAILY MEAN.
Importance of selecting hours in calculating the mean.—Arbitrary values of many of the previous publications.—
6h + 2h + 10h 7h + 2h + 2 X 9h SB. + 41'
Combinations generally used: -. -. max. and mm. -.—
s J 3 4 2
Comparison of the results.
Before extending the considerations about variation to the yearly period the
calculation of the mean has to be analysed, as it is the selection of the hours of observ-
ation and their combination which so materially modify every result when hourly
observations cannot be procured.
The meteorological registers as proposed for India by the Medical Board, were
intended to contain when complete, Sunrise, 9h 50' a.m., Noon, 2h 40' p.m., 4h p.m., Sunset,
10h p.m. These hours were to include the extremes of heat and pressure, and presented
at the same time observations sufficiently numerous and with the desirable intervals.
Occasionally also registering instruments were employed.
In the manuscript materials I could procure 10'1 p.m. is observed scarcely any-
where, whilst SB., 41' p. m., and 88. are those most generally kept up.
The hours of observation used by the continental observers of Europe are most
generally 6" a.m., 2" p.m., 10h p.m., or 7h a.m., 2h p.m., 9h p.m.; these hours are selected
with a more direct view to the final calculation of the true mean.
In order to deduce the daily mean from a limited number of observations, the distri-
bution of the hours, or, if the readings are made already, the selection of those to be
combined, is a matter of the greatest importance. When I come to examine the
materials officially published, it will be seen that the "daily means" sent to Europe,
as also those recently published in the Parliamentary Sanitaria Beports, were some-
13*
Importance of selecting hours in calculating the mean.—Arbitrary values of many of the previous publications.—
6h + 2h + 10h 7h + 2h + 2 X 9h SB. + 41'
Combinations generally used: -. -. max. and mm. -.—
s J 3 4 2
Comparison of the results.
Before extending the considerations about variation to the yearly period the
calculation of the mean has to be analysed, as it is the selection of the hours of observ-
ation and their combination which so materially modify every result when hourly
observations cannot be procured.
The meteorological registers as proposed for India by the Medical Board, were
intended to contain when complete, Sunrise, 9h 50' a.m., Noon, 2h 40' p.m., 4h p.m., Sunset,
10h p.m. These hours were to include the extremes of heat and pressure, and presented
at the same time observations sufficiently numerous and with the desirable intervals.
Occasionally also registering instruments were employed.
In the manuscript materials I could procure 10'1 p.m. is observed scarcely any-
where, whilst SB., 41' p. m., and 88. are those most generally kept up.
The hours of observation used by the continental observers of Europe are most
generally 6" a.m., 2" p.m., 10h p.m., or 7h a.m., 2h p.m., 9h p.m.; these hours are selected
with a more direct view to the final calculation of the true mean.
In order to deduce the daily mean from a limited number of observations, the distri-
bution of the hours, or, if the readings are made already, the selection of those to be
combined, is a matter of the greatest importance. When I come to examine the
materials officially published, it will be seen that the "daily means" sent to Europe,
as also those recently published in the Parliamentary Sanitaria Beports, were some-
13*