288 Report of the Voyage of Discovery 
average of ten days observations give very nearly the same 
degree. 
The consideration of the absolu¢e temperatures would fur- 
nish a proof not less certain of the existence of this current of 
cold water. At the port of Callao, from the 26th of February 
to the 4th of March, the mean temperatures of the air and of 
the sea were respectively 21°°3 and 19°°1. Cent. At sea, 
at 800 leagues from the coasts, under the same latitude, 
as also under a higher latitude, they found, from the 7th to 
the 10th of April, 25°-9 and 25°°6. At Payta, from the 10th 
to the 22d of March, the mean temperatures of the air and 
water which we deduce from the journals of the Coquille are 
25°*1 and 20°°0. Here the current no longer exercises, as it 
appears, a very great influence on the temperature of the at- 
mosphere near the coast; but it is still 6 or 7 degrees colder 
than the ocean at a similar latitude in all other parts of the 
sea. ; 
We applied ourselves to this investigation of some of the 
meteorological observations made by M. Duperrey, in order 
to show how desirable it would be that they should be printed 
entire; the physical sciences and even the nautical art would 
derive great advantage from this. May it also be permitted us, 
in closing this article, to express the regret which we have 
felt, in not finding in such rich and valuable journals, some 
observations of the temperature of the sea at great depths. 
This inquiry, so directly connected with that of the existence 
of submarine currents, would nevertheless not have retarded 
the sailing of the Coquille a quarter of an hour, since in ge- 
neral it would have sufficed to have attached a thermometer to 
the deep-sea-lead every time it was thrown into the sea. If 
experiments so interesting were completely neglected by 
M. Duperrey and his fellow-labourers, it is almost needless to 
say that it was only because the means of making them with 
exactitude were wanting. ‘There was not indeed on board 
the corvette one of those ingenious thermometers which mark 
by indexes the maxima and minima of temperature to which 
they have been exposed. 
An expedition for discovery seldom leaves our ports with- 
out the Academy being consulted by the public authorities, 
even without their requiring it, to prepare the instructions 
for the commander. We think that it would contribute in a 
manner not less efficacious to the progress of the sciences, if 
it caused to be prepared before-hand, by the most skilful 
artists, some of the philosophical instruments which the na- 
vigators might want. If the Academy, as we hope, shall deign 
to 
