124 On the Sea and Land Rates of Chronometers. 
sing contrivances to remedy an evil which has no practical existence 
where the common discretion of life is exercised in obtaining the bet- 
ter article at an equal price. 
‘‘ Had the especial purpose of the Hecla’s voyage been to inquire * 
whether the iron of a ship, in its ordinary distribution, would, under 
extreme circumstances, exert a sensible influence on the chronome- 
ter, better adapted arrangements could scarcely have been devised 
for the experiment, nor could a more decisive result in the negative 
have heen obtained. 
“The Hecla was stationary and ee being, frozen up, for 
more than ten months in the vicinity of the magnetic pole, the dip 
being between eighty eight and eighty nine degrees: such is the sit- 
uation, and such the circumstances, which are supposed to be best 
adapted for the developement of magnetism in the stancheons, and 
other vertical iron of aship. ‘The chronometers were kept on board 
the whole winter, and their rates, preparatory to the polar navigation 
of the following summer, were assigned from the average of the four 
months immediately preceding her extrication from the ice, at an 
equal period of four months of navigation. ‘The Hecla arrived at 
Leith, having experienced much bad weather in crossing the Atlan- 
tic but on comparing the four chronometers at the Observatory at 
Leith, their Greenwich time, employing the winter harbor rates, 
proved less than two seconds in error. 
“On the arrival of the Hecla in the Thames, the chronometers 
were returned to Messrs. P. and F.’s house in London, when, after 
a month’s interval, they were found to be still going at the same rate 
as inthe Hecla whilst in the harbor of Melville Island.” 
Attention was first, we believe, drawn formally to the supposed al- 
teration of the rates of chronometers on their removal on ship board 
by the Rev. Mr. Fisher, who found that the rates of those in his 
charge were uniformly accelerated under such circumstances; and 
he assigned as the cause, the magnetic effect of the iron, to which 
Captain Sabine, in the above has so pointedly adverted. 
Many persons well acquainted with the subject were of opinion 
at the time of the publication of Mr. Fisher’s memoir, that from the 
obvious inferiority of the chronometers which he used, no authori- 
tative inference could be drawn from any anomalies which their 
rates might exhibit,—an opinion in which we fully concur. 
One of these chronometers had a rate on board of 3” 4’; but, on 
its removal to the Observatory, its rate was found to be 18’ a7 ; and 
