during the Expedition under Captain Parry. 207 
The times of High Water on full and change days of the 
moon in Winter Harbour were as follows : 
New Moon, May 12. 1820, - l h 15' 
Full, 27. - 1 45 
New, June 10. - 1 15 
New, July 10. - 1 40 
Mean time of high-water on full and change, 1 29 
Experiments with the Pendulum . — As a full detail of these ex- 
periments will be published in the Philosophical Transactions 
for 1821, Captain Sabine has given only a brief statement of 
the results, which are as follows: 
From the Acceleration between 
London and Brassay, 
London and Hare Island, 
Brassay and Hare Island, 
London and Melville Island, 
Audibility of Sounds . — Captain Parry was surprised at the 
great distance at which sounds were heard in the open air, du- 
ring the continuance of intense cold ; and, notwithstanding the 
frequency with which they had occasion to remark it, it always 
afforded them surprise. “ We have, for instance,” says he, 
“ often heard people distinctly conversing, in a common tone of 
voice, at the distance of a mile ; and to-day I heard a man sing- 
ing to himself as he walked along the beach, at even a greater 
distance than this.” 
As Captain Parry does not seem to be aware of the cause of 
this very curious and important fact, we shall endeavour to 
explain it, upon principles which Humboldt has ably developed, 
in a paper on the Increase of Sounds during Night, (See 
this Journal, vol. iii. p. 194.) If the air were at all times of 
uniform density, the sounds propagated through it would al- 
ways be of the same intensity ; but in the day time, the in- 
equality with which different parts of the ground are heated 
occasions a difference of density in the adjacent air, and thus 
Diminution of Gravity 
from the Pole to the 
Ellipticity of 
Equator. 
the Earth, 
•0055066 
1 
314,3 
•0055139 
1 
313,6 
1 
•0055082 
— 
314,2 
•0055258 
1 
312,6 
