'The Transactions of the Bombay Geographical Society. From January 1863 to December 1864. (Edited by the Secretary.) Volume XVII.' [‎14] (175/524)

14
REMAItKS ON THE
Again, the observed time of high-water August 21st, is in error—
By Professor Orlebar’s formula . 15m. early.
By the First Constant 31
By the Second Constant 2/
By the Third Consttint 35 ))
By the Fonrth Constant 26
By each of the first three methods, the number of tides registered
at times later than the computed is fully double those registered
earlier, and the average error late is more than double the error of
those apparently too early. The third and fourth constants bring both
the number and amount of errors nearer to an equality ; but these
constants having been chosen so as to bring the algebraic sum of the
errors nearly to zero, both are probably a few minutes less than the
values which theory indicates. In this all agree—that the mean
error of those observations that are too late, exceeds the mean error
of those which are too early. Thus the average errors of the obser
vations as indicated by the different approximations are^—
Average
Average
Mean
error too
error too
error of
•
late.
early.
all.
m.
m.
m.
By Professor Orlebar’s formula
. 3L8
24-6
29-0
By the First Constant, or -f 9A. 31m.. . .
. • 37-8
15-5
30-3
By the Second Constant, or — 2h. 50m. ..
33-5
16*5
27’2
Bylthe Third Constant, or —14^. 59m...
30-4
21-6
24'6
By the Fourth Constant, or— 27h. 24m. .
26-6
25-2
25’3
In t\iQ Memoires de T Academie, ISIS, Laplace says, “Uest temps
enfin d observer ce genre de p ) Lenomenes avec autant de soin que les
phenomenes astronomiques, 5 ’^ and more than forty yea'rs afterwards
we have observations chronicled, in which there are not merely a few
observations which fall considerably.short of an approach to the accu
racy with which all astronomical phenomena are recorded, but among
which errors are so numerous and so great, that the mean numerical
error of each of a whole series of more than 330 observations amounts to
not less than from 25m. to 30m. I need not say how disappointing
such a result as this is : not only is one year’s observations almost lost,
hut ? CC0 , imt ** or some °f tire errors, and perhaps entirely for other
and often consider abb. 611 int ° account > the discrepancies will still be ma
* Memoires de I’Academie, 1818, page 2.