V0YACE FOR THE DISCOVERY OF SOUTHERN LANDS.

753

told by their predeceffors, and neglecting all the real novelty to be found in this im-menfe field, comprehending at once the whole length of the Atlantic Ocean , theIndian Sea , the two temperate zones, and the equatorial belt of the world. Yet,what a valuable fucceffion of obfervations might there not, in fuch a voyage, be madeon the atmofphere, and its temperature in different latitudes of the one and otherhemifphere, on the variations of the barometer and hygrometer under fimilar circum-ftances ! On the temperature of the fea alfo, at its furface, compared with that ofthe atmofphere at different parts of the day and the night! And the warmth of thefea, at great depths, does it not prefent a career fecund in refults of greatefl intereft ?Are we not moreover reduced to vain conjectures on the depth of the fea, and therelative proportion of the faltnefs of its waters ? Our opinions are they not flill irre-folute refpeCting the real caufe of the phofphorefcence of the fea, of this marvellousphenomenon, fo common, yet fo ill explained, and, it might be faid, fo ill examinedtill the prefent day ? And carting the eye over the wide expanfe of the ocean, arethere not a crowd of pelagic animals, of mollufcte, and zoophytes efpecially, whichmight be difcovered, and only wait, to exhibit new prodigies, a fearch into their organi-zation, an hiftorian of their mode of life ?

Here, certainly, are fubjeCts for obfervation, numerous enough and fufficiently at-tractive, to be purfued during the long voyage in queftion; fubjeCts, on which attentionwould far better be fixed than on flying-fifhes, dorados, {harks, and their pilots # , &c.To voyages of fuch defcription, and to thefe alone, does it belong to furnilh theprecious materials of a phyfical and meteorological chart of the fea, a chart ofwhich fcience deplores the want, and the moft fimple elements of which it would feek.in vain in heaps of narratives, mere repetitions the one of the other.

- In directing my attention to the feveral fubjeCts I have detailed, I was defirous ratherof pointing out this new career, than of boafting on account of my having purfued it;but the refults I have obtained from thefe firft attempts appear to me of fufficientutility to claim a fummary expofition in this work ; the minutiae of the obfervations ofwhich thefe are the fruits I referve for other occafions, and for other works.

SECTION I. — Meteorological Obfervations.

THESE obfervations were made with the thermometers of Dollond and Moffy, thebarometers of the latter artift, and the hygrometers, with double hairs, of Richer.That the obfervations might better be compared, I made a point of repeating them fourtimes every day at the moft oppofite hours, that is to fay, at fix, night and morning, atnoon and midnight. The obfervations were commenced with the voyage, were madein the open air in all weathers, and on the quarter deck. The firft feries of my laboursfurnilhed me with the following general refults.

Indications of the Thermometer.

1. The temperature, under fimilar circumftances of weather, rifes progreffively"with an advance towards the equator.

2. It progreffively falls in failing from it.

3. The proportion of its rife and fall is not the fame in either hemifphere; the meanof the heat in the fouthern being lefs than in the correfponding northern latitudes.

* The-remora is called the pilot-fifli, from its conftantly preceding the (hark, and pointing out to it*ts prey. Tr.

vol. xi. 5» 4. Under