126 
The Australasian Scientific Magazine. [Nov. i, 1885. 
reference to ocean currents. In paragraph eighteen (18) he says — “ I he 
facts from observation, on this interesting subject, afford us, at best, but a 
mere glimmer of light, by no means sufficient to make any mind clear as to 
the sufficiency of any of the causes generally assigned for this wonderful 
stream.” As the Gulf Stream is only the continuation of the great 
equatorial current flowing regularly and constantly from east to west across 
the Atlantic Ocean, this remark inferentially applies to it, and similarly to 
all the currents of the ocean, flow in whatsoever direction they may, seeing they 
are all dependent upon each other, and form but the parts of one stupendous 
whole. The only cause which Maury has been able to assign in partial 
explanation of these phenomena, is heat. He admits its insufficiency, 
however, and shows that some yet unacknowledged force must be revealed 
to account for their production, which force he estimates as “ at least 
sufficient to drive at the rate of three miles the hour ninety thousand mil- 
lions of tons up an inclined plane having an ascent of three inches to the 
mile.” Heat he considers inadequate to the performance of this duty. 
Where then is the primum mobile to be found? 
And heat is not only insufficient to put the great equatorial currents ui 
motion at the rate with which they move, but neither can axial rotation by 
any means be made adequately to explain the westwardly direction of their 
motion at the velocity which they uniformly maintain. Maury certainly 
states that as the result of heat we should have “ a perpetual and uniform, 
system of tropical and polar currents,” and axial rotation should have the 
effect of giving all the currents from the equator to the poles “ an eastward 
tendency, and all from the poles to the equator a westward.” But whilst 
this is theoretically correct the high velocity and direct westward motion of 
the great equatorial currents are an acknowledged mystery, seeing that the 
influence of axial rotation on currents travelling from inside the tropics to- 
wards the equator is practically nil ; and Maury does not anywhere attempt 
to suggest an adequate cause for these phenomena. Hughes in his text 
book makes the very same remark as quoted above from Maury, but im- 
mediately afterwards he goes on to say that heat and axial rotation “ will 
account for the existence of ocean streams or currents, and explain their 
general direction,” such general direction being “ within tropical latitudes 
to the westward, within temperate latitudes to the eastward.” These con- 
flicting statements are evidence of a confusion of ideas arising from the 
failure hitherto to state a theory which will properly account for the exist- 
ing facts. 
With reference to the winds, Maury admits that there are many things 
hard to be understood, and impossible of explanation by any theory on 
the subject which has yet been suggested. In his chapter on the At- 
mosphere he points out that Halley’s theory, which with trifling 
modifications has been adopted by nearly all subsequent writers on the 
subject, is not conclusive. In paragraph 128 he states as follows: — 
“ Halley, in his theory of the trade winds, pointed out the key to the 
explanation so far of the atmospherical circulation ; but were the explana- 
tion to rest here, a north-east trade wind extending from the pole to the 
equator would satisfy it ; and were this so we should have on the surface 
no winds but the north-east trade winds on this side, and none but south-east 
trade winds on the other side of the equator.” Maury goes on to show that 
such is not the case, and the reason of the deviation he confesses to be 
unable to explain. He informs us that a particle of air setting off from the 
polar regions, “ for some reason which does not appear to have been very 
