580 PHILOSOPHICAL TRANSACTIONS. [aNNO \6Q3. 



Several notable corollaries follow from this rule. As 1 . that the equinoctial 

 heat, when the sun becomes vertical, is as twice the square of radius ; which 

 may be proposed as a standard to compare with in all other cases. 2. That under 

 the equinoctial, the heat is as the sine of the sun's declination. 3. That in the 

 frigid zones, when the sun sets not, the heat is as the circumference of a circle 

 into the sine of the altitude at 6 : and consequently, that in the same latitude, 

 these aggregates of warmth are as the sines of the sun's declinations ; and in 

 the same declination of sol, they are as the sines of the latitudes ; and generally 

 they are as the sines of the latitudes into the sines of declination. 4. That the 

 equinoctial day's heat is every where as the co-sine of the latitude. 5. In all 

 places where the sun sets, the difference between the summer and winter heats, 

 when the declinations are contrary, is equal to a circle into the sine of the 

 altitude at 6 in the summer parallel ; and consequently those differences are as 

 the sines of latitude into, or multiplied by, the sines of declination. 6. From 

 the table it appears, that the tropical sun under the equinoctial has of all 

 oihersthe least force : under the pole it is greater than any other day's heat 

 whatever, being to that of the equinoctial, as 5 to 4. 



From the table, and these corollaries, may a general idea be conceived of the 

 sum of all the actions of the sun in the whole year, and that part of heat which 

 arises simply from the presence of the sun be brought to a geometrical certainty: 

 and if the like could be performed for cold; which is something else than the 

 bare absence of the sun, as appears by many instances, we might hope to bring 

 what relates to this part of meteorology to a perfect theory. 



^4n Account of Books, viz. — 1 . Diogenes Laertius Greece et Latine, cum Com- 



mentariis integris Doctorum Firorum Amstelodami. Typis Henrici IVelstenii, 



Anno 1692. N°203, p. 886. 



The ten books of Diogenes Laertius, containing the lives, sayings, and opi- 

 nions of the most ancient and eminent philosophers of Greece, have been 

 printed a great many times. 



This edition is said to have many advantages over all the former ; and it is 

 said that this age has not seen any work performed with so great fidelity, accu- 

 racy, elegancy, and perfection in all points, as we see meet here in this edition. 



2. Considerations on a Booh entituled, the Theory of the Earth: published some 

 Years since by the learned Dr. Burnet. Written by John Beaumont, jun. Gent. 

 N°203, p. 888. 

 Though several persons before had printed some reflections on this theory, 



the author of these considerations, arguing generally in a way different from 



