226 



3Iaximum at 



3 Feet. 6 Feet. 12 Feet. 24 Feet. 



Observatory, August 6. September 2. October 1 7. January 8. 



Exper. Gar. July 31. August 24. October 7- December 30. 



Craigleith, August 5. August 19. September 11. November 11. 



We also find, as theory assigns, the retardation of the maximum 

 increases arithmetically with the depth. So that, if we project 

 these observations and cause an interpolating straight line to pass 

 through the points for each station, we find that the progress of heat 

 downwards is. 



At the Observatory, 1 foot in 7-5 days. 



Experimental Garden, 7-1 



Craigleith Quari-y, 4.9 ... 



giving the same order of conducting power as before. 



The bearing of these experiments on geological theories, and es- 

 pecially on the movement of the Isothermal lines in the interior of 

 the globe, is evident. 



Monday, llt/i December 1838. 

 Dr ABERCROMBIE in the Chair. 

 The following Donations were presented : 



Memoires Couronnes par I'Academie Royale des Sciences et Belles 



Letti-es de Bruxelles. Tomes xii. and xiii. 

 Bulletin des Seances de I'Academie Royale des Sciences et Belles 



Lettres de Bruxelles. 1837, Nos. 10, 11, 12. 1838, Nos. 1, 



2, 3, 4, 5, 6, 7, 8. 

 Annuaire de I'Academie Royale des Sciences et Belles Lettres de 



Bruxelles pour I'an 1838. Bi/ the Academy. 



Annuaire de I'Observatoire de Bruxelles pour I'an 1838, par le Di- 



recteur A. Quetelet. — Bi/ the Author. 

 De rinfluence des Saisons sur la Mortalite aux difi«rens Ages dans 



la Belgique, par A. Quetelet. — By the Author. 

 Resume des Observations Meteorologiques faites en 1837 a I'Obser- 

 vatoire de Bruxelles, et communiquees par A. Quetelet. — By 



the Author. 

 Recherches sur les Proprietes des Courants Magneto-Electriques, 



par M. le Prof. Aug. de la Rive. — By the Author. 

 Examen Critique d'un Memoire de M. P. Leroux, intitule du Bon- 



heur, par L. A. Gruyer — By the Author. 



