decline of science in england-第17章
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29th Aug。 。 。 。 31。8 43。8 Alph。Pavonis； 29th Aug。 。 。 44；0 44。5 Alph。Lyrae； 31st Aug。 。 。 。 42。6 44。6 Alph。Cygni； 31st Aug。 。 。 。 39。2 42。0 Alph。Gruris； 2d Sept。 。 。 。 27。4 42。2
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； &c。 PAR MM。 BIOT ET ARAGO； which forms the fourth volume of the BASE DU SYSTEME METRIQUE。＇ are filled with the details relative to the determination of the value of the divisions of the level。 It would also have been satisfactory； with such an important object in view； to have read off some of the sets after each pair of observations； in order to see how far the system of repetition made the results gradually converge to a limit； and in order to know how many repetitions were sufficient。 Such a course would almost certainly have led to a knowledge of the true value of the divisions of the level； for the differences in the altitude of the same star； after a few minutes of time； must； in many instances； have been far too great to have arisen from the change of its altitude： and had these been noticed； they must have been referred to some error in the instrument； which could scarcely； in such circumstances； have escaped detection。
I have now mentioned a few of the difficulties which attend Captain Sabine's book on the pendulum； difficulties which I am far from saying are inexplicable。 He would be bold indeed who； after so wonderful an instance of the effect of chance as I have been just discussing； should venture to pronounce another such accident impossible； but I think enough has been said to show； that the feeling which so generally prevails relative to it； is neither captious nor unreasonable。
Enough also has appeared to prove； that the conduct of the Admiralty in appointing that gentleman one of their scientific advisers； was； under the peculiar circumstances； at least； unadvised。 They have thus lent； as far as they could； the weight of their authority to support observations which are now found to be erroneous。 They have thus held up for imitation observations which may induce hundreds of meritorious officers to throw aside their instruments； in the despair of ever approaching a standard which is since admitted to be imaginary； and they have ratified the doctrine； for I am not aware their official adviser has ever even modified it； that diminutive instruments are equal almost to the largest。
To what extent this doctrine is correct； may perhaps yet admit of doubt。 It cannot； however； admit of a doubt； that it is unwise to crown it with official authority； and thus expose the officers of their service to depend on means which may be quite insufficient for their purpose。
How the Board of Longitude； after EXPRESSLY DIRECTING THIS INSTRUMENT TO BE MADE AND TRIED； could come to the decision at which they arrived； appears inexplicable。 The known difference of opinion amongst the best observers respecting the repeating principle； ought to have rendered them peculiarly cautious； nor ought the opinion of a Troughton； that instruments of less than one foot in diameter may be considered； 〃FOR ASTRONOMY； AS LITTLE BETTER THAN PLAYTHINGS；〃 ＇Memoirs of the Astronomical Society； Vol。I。 p。53。＇ to have been rejected without the most carefully detailed experiments。 There were amongst that body； persons who must have examined minutely the work on the Pendulum。 Captain Kater must have felt those difficulties in the perusal of it which other observers have experienced； and he who was placed in the Board of Longitude especially for his knowledge of instruments； might； in a few hours； have arrived at more decisive facts。 But perhaps I am unjust。 Captain Kater's knowledge rendered it impossible for him to have been ignorant of the difficulties； and his candour would have prevented him from concealing them： he must； therefore； after examining the subject； have been outvoted by his lay…brethren who had dispensed with that preliminary。
It would be unjust； before quitting this subject； not to mention with respect the acknowledgment made by an officer of the naval service of the errors into which he also fell from this same level。 Lieutenant Foster； aware of the many occasions on which Captain Sabine had employed this instrument； and knowing that he considered each division as equal to one second； never thought that a doubt could exist on the subject； and made all his calculations accordingly。 When Captain Kater made him acquainted with the mistake； Lieutenant Foster immediately communicated a paper ＇The paper of Lieutenant Foster is printed in the Philosophical Transactions； 1827； p。122； and is worth consulting。＇ to the Royal Society； in which he states the circumstance most fully； and recomputed all the observations in which that instrument was used。 Unfortunately； from the original observations of Mr。 Ross being left on board the Fury at the time of her loss； the transcripts of his results could not be recomputed like the rest； and were consequently useless。
SECTION 5。
OF THE UNION OF SEVERAL OFFICES IN ONE PERSON。
Although the number of situations to which persons conversant with science may hope to be appointed； is small； yet it has somewhat singularly happened； that instances of one individual； holding more than one such appointment； are frequent。 Not to speak of those held by the late Dr。 Young； we have at present：
MR。 PONDAstronomer Royal； Inspector of Chronometers； and Superintendent of the Nautical Almanac。
CAPTAIN SABINE An officer of artillery on leave of absence from his regiment； Secretary of the Royal Society； and Scientific Adviser of the Admiralty。
MR。 BRANDEClerk of the Irons at the Royal Mint； Professor of Chemistry at the Royal Institution； Analyser of Rough Nitre； &c。 to the East…India Company； Lecturer on Materia Medica； Apothecaries' Hall； Superintending Chemical Operator at ditto； Lecturer on Chemistry at ditto； Editor of the Royal Institution Journal； and Foreign Secretary to the Royal Society。
One should be led to imagine； from these unions of scientific offices； either that science is too little paid； and that gentlemen cannot be found to execute the offices separately at the salaries offered； or else； that it is too well paid； since each requires such little attention； that almost any number can be executed by one person。
The Director of the Royal Observatory has a larger and better collection of instruments； and more assistants to superintend； than any other astronomer in the world； and； to do it
