Welcome to my first blog

Hammerfest Sun 70 40 5



Spitzbergen Sun 79 49 56

Sun 55

Sun 58

Sun 59

Sun 55

Sun 50 1



Greenland Sun 74 32 19

Sun 17



Drontheim Sun 63 25 51

Alph





This presents a very different view of the latitudes as

determined by the small repeating circle, from that in Captain

Sabine's book; and confining ourselves still to Maranham, where

the latitudes "WERE OBTAINED, WITH ESPECIAL REGARD TO EVERY

CIRCUMSTANCE BY WHICH THEIR ACCURACY MIGHT BE AFFECTED," and

where "A MORE THAN USUAL ATTENTION WAS BESTOWED," it appears,

that if we take Captain Sabine's own test, namely, "the

differences of the partial results from the mean at each

station," the deviations become nearly ten times as large as they

were before; a circumstance which might be expected to have some

influence in the decision of the question



There is, however, another light in which it is impossible to

avoid looking at this singular oversight The second column of

the table of latitudes must now be considered the true one, as

that which really resulted from the observationsNow, on

examining the column of true latitudes, the differences between

the different sets of observations is so considerable as

naturally to excite some fear of latent error, more especially as

nearly the greatest discordance arises from the same star,

Alphyrae, observed after an interval of only three days It

becomes interesting to every person engaged in making

astronomical observations, to know what is the probability of his

being exposed to an error so little to be guarded against, and so

calculated to lull the suspicions of the unfortunate astronomer

to whom it may happen



In fact, the question resolves itself into this: the true

latitude of a place being determined by sets of observations as

in the first of the following columns--



Latitudes as

True latitudes observed computed by a mistake

of Capt



deg 44,0 44



what are the chances that, by one error all the latitudes in the

first column should be brought so nearly to an agreement as they

are in the second column? The circumstance of the number of

divisions of the level being almost arbitrary within limits,

might perhaps be alleged as diminishing this extraordinary

improbability: but let any one consider, if he choose the error

of each set, as independent of the others, still he will find the

odds against it enormous



When it is considered that an error, almost arbitrary in its law,

has thus had the effect of bringing discordant observations into

an almost unprecedented accordance, as at Maranham; and not

merely so, but that at eight of the nine stations it has

uniformly tended to diminish the differences between the partial

results, and that at the ninth station it only increased it by a

small fraction of a second, I cannot help feeling that it is more

probable even that Captain Kater, with all his admitted skill,

and that Captain Sabine himself, should have been both mistaken

in their measures of the divisions of the level, than that so

singular an effect should have been produced by one error; and I

cannot bring myself to believe that such an anticipation is

entirely without foundation



Whatever may be the result of a re-examination, it was a singular

oversight NOT TO MEASURE the divisions of a level intended to be

used for determining so important a question; more particularly

as, in the very work to which reference was made by Captain

Sabine for the purpose of comparing the observations, it was the

very first circumstance which occupied the French philosophers,

and several pages [See pages 265 to 275 of the RECUEIL

D'OBSERVATIONS GEODESIQUES,

Welcome to my first blog

"Canadians Look Forward to 2010 with Caution, Optimism
"

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