136 Miscellaneous. 



and 74° ;* in September, in the early part of the month, it was variable, 

 the average being about 82°, while towards the end it became consider- 

 ably lower and more settled, 74° being the average of the last few days 

 and early part of October, when the cold season was evidently regularly 

 setting in to last, (say those who have voyaged in the higher latitudes 

 on the coast,) till near the close of the N. E. Monsoon, that is, till 

 about the end of March, when the warm weather again takes prece- 

 dence, increasing the temperature until June, July, and August, which 

 are the hottest months of the year. The best support to this opinion 

 is furnished by the return of the Officers as contrasted with that of the 

 men, during the first four months of our occupation. 



Had these evils pressed less heavily upon the troops, had measures 

 been resorted to to keep both mind and body in a state of activity with- 

 out overpowering the latter with a labour to which it had long been 

 unaccustomed, and had the means which the island afforded of furnish- 

 ing a certain description and quantity, though limited, of fresh provisions, 

 been fully availed of, there appears little room to doubt that the men 

 would have exhibited no more deterioration in efficiency than the first 

 exposure to a new climate must entail, and have been found at the ter- 

 mination of the winter season ready, and fully equal to any exposure 

 and privation which the service might have called upon them to 

 endure. 



Geology. — The prevailing rock of the island belongs to the ancient 

 volcanic class, and comprises many varieties, but principally clay stone, 

 clay stone porphyry, felspar, compact and porphyritic and trachyte. 



In portions of the cliffs on the S. and N. coasts the rocks are observ- 

 ed to assume a columnar structure, and dykes and masses of greenstone 

 burst through the beds of claystone on various points, indurating and 

 altering them to a considerable extent. On the W. coast the claystone 

 porphyry assumes a slaty or laminated structure, and appears to be 

 quarried extensively both for use on the island and for exportation to 

 the main land, affording excellent slabs for paying and for floors, and 

 good blocks for common building purposes. A coarse conglomerate is 

 also to be seen intervening between beds of the claystone, embedding 

 angular fragments of many descriptions of igneous rocks, and passing 

 into a compact and workable porphyry, which is also quarried and 

 made use of for pillars, blocks for corn mills, basement slabs, &c. &c. 

 The very best materials for road-making and repairing are readily 



* During this month the vicissitudes in the temperature were occasionally considerable, as 

 for example on the 18th the Mercury stood at 96o- at noon, while on the 19th in the same loca- 

 lity and under similar circumstances it registered 75o. 



