304 Mr. Redfield on the 
the alternate geographical declination of the sun, nor to the actual 
geographical change in the zone of greatest temperature, which 
follows the sun’s declination.* 
The semiannual change of the locality in the trade winds is 
believed to be greatest in the Atlantic, where it does not ap- 
pear to average more than 7° or 8° of latitude; while the annual 
range of the sun’s declination exceeds 46°, and the actual trans- 
fer of the zone of heat, which follows the declination, appears to 
be nearly 40° of latitude. These facts, also, I deem to be con- 
clusive against the theory. 
5. Even within the ordinary geographical limits of the trade 
winds, there are extensive portions of the system of winds which, 
in their course and direction, do not accord with the received 
theory, but appear wholly irreconcilable with its requirements. 
‘To illustrate this objection, I refer, first, to a circuit of inter- 
tropical winds in the equatorial basin of the North Atlantic) which 
appears to extend from the delta of the Quorra, the ancient Niger, 
for more than two thirds the distance to the coast of South Amer- 
ica; in which circuit the winds revolve to the right, with more 
or less of regularity, around a central and probably elongated 
axis. And second, to the existence and great extension into open 
sea of those portions of the monsoon winds which blow obliquely 
Jrom the equator, in directions where there can be none of the 
continental *rarefaction which has been alleged as explaining 
these alternating winds. For if the winds of the equatorial lati- 
tudes rise to the higher regions, the monsoon winds of the Indian 
Ocean, on departing from the south side of the equator, could 
never be made to sweep eastwardly upon the earth’s surface for 
even six thousand miles, as they now do annually, instead of as- 
cending four or six miles in altitude, to flow off from the equator 
as superior winds.{ 
* In other words, an essential geographical change in the locality of heat, of some 
months’ duration, does not change, materially, the locality of the trade winds. 
Hence, these winds are not, mainly, the result of heat. 
t M. Bougainville says, ‘‘ from the 23d of February to the 3d of March, we had 
westerly winds, constantly varying between S. W. and N. W., with calms and 
rains ; every day either a little before noon or soon after, we had sudden gusts of 
rain accompanied with thunder. It was strange to us to meet with this extraordi- 
nary wind under the tropic, and in that ocean so much renowned above all other 
seas for the uniformity and freshness of the E, and 8. E. trade winds; which are 
