11 



small tliat influence may be supposed to be ; for be it great or small, we may rest assured it is not a chance 

 influence, but it is an influence exercised — if exercised at all — by design, and according to the command- 

 ment of Him whose " voice the winds and the sea obey." 



It may therefore be supposed that the arrangements in the economy of nature are such as to require that 

 the various kinds of marine animals, whose secretions are calculated to alter the specific gravity of sea water, 

 to destroy its equilibrium, to beget currents in the ocean, and to control its circulation, should be distributed 

 according to order. 



Upon tliis supposition — the like of which nature warrants throughout her whole domain — we may conceive 

 how the marine animals of which we have been speaking, assist also to regulate climates and to adjust the tempera- 

 ture of certain latitudes. For instance, let us suppose the waters in a certain part of the Torrid Zone to be 70°, 

 but by reason of the fresh water which has been taken from them in a state of vapor, and consequently by 

 reason of the proportionate increase of salts, these waters are heavier than waters that may be cooler but not 

 so salt. This being the case, the tendency would be for this warm but salt and heavy water to flow off as an 

 under current towaids the Polar or some other regions of lighter water. 



Such an under current, by reason of the limited conducting powers of water for heat, would preserve its 

 high temperature for a length of time, and for great distances — cooling, of course, somewhat by the way. 



This under current may be freighted with heat to temper some hyperborean region, or to soften some 

 extratropical climate ; for we know that such is' among the effects of marine currents. At starting it might 

 have been, if you please, so loaded with solid matter that though its temperature were 70°, yet by reason of 

 the quantity of such matter held in solution, its specific gravity might have been greater than that of extratropi- 

 cal sea water generally at 28°. 



Notwithstanding this, it maybe brought into contact, by the way, with those kinds and quantities of marine 

 organisms that shall abstract solid matter enough to reduce its specific gravity, and instead of leaving it greater 

 than common sea water at 28°, to make it less than common sea water at 40° ; consequently, in such a case 

 this warm sea water, when it comes to the cold latitudes, would be brought to the surface through the instru- 

 mentality of shell fish and various other tribes that dwell far down in the depths of the ocean. Thus we 

 perceive that these creatures, though they are regarded as being so low in the scale of creation, may, neverthe- 

 less, be regarded as agents of much importance in the terrestrial economy, for we perceive that they are capable 

 of spreading over certain parts of the ocean those benign mantles of warmth which temper the winds and modify, 

 more or less, all the marine climates of the earth. 



The makers of nice astronomical instruments, when they have put the diflferent parts of their machinery 

 together and set it to work, find as in the chronometer for instance, that it is subject ir its performance to 

 many irregularities and imperfections. That in one state of things, there is expansion, and in another state 

 contraction among cogs, springs and wheels with an increase or diminution of rate. This defect, the makers 

 have sought to overcome ; and with a beautiful display of ingenuity, they have attached to the works of the 

 instrument a contrivance which has had the efl^ect of correcting those irregularities, by counteracting the 

 tendency of the instrument to change its performance with the changing influences of temperature. 



