190 Mr. Moyles Meteor ologicalJ our nal [March, 



ments of Hope, Murray, and Traill, permit us no longer to doubt, 

 what difficulty is there in conceiving, that a peculiar modifica- 

 tion of it should also be transmitted through the same medium. 



But it may be asked, allowing the validity of this theory to 

 account for the deposition of the first stratum of ice, why does 

 not each succeeding layer as fast as it is formed take that situa- 

 tion which its lesser specific gravity would assign to it, and rise 

 to the surface of the water. This at first sight would appear a 

 very formidable objection : it must, however, be recollected that 

 this '' ascensional " effort will only be exerted when the con- 

 gealed mass is surrounded on every side by water. The aqueous 

 ciystals, as they may be termed, shooting from all the prominent 

 points of the bottom, would, by their intertexture, become firmly 

 infixed to the inequalities of the ground, and prevent the water 

 from insinuating itself beneath." The continual deposit of sand 

 and mud must likewise contribute to keep it sunk. 



I am fully aware that the few remarks 1 have here ventured to 

 offer on this curious and interesting subject require the support 

 of actual experiment in order to give them the stability of a per- 

 manent theory. This, however, I leave to those whose leisure 

 or abilities better qualify them for such pursuits. In the mean 

 time they may supply the plan of more important information on 

 the subject, and may, perhaps, be the means of turning the 

 attention of chemists to the investigation of a phenomenon 

 which has hitherto baflied all inquiry. 



Article VII. 



Meteorological Journal kept at Helston, Cornwall, for 1821. 

 By Mr. M. P. Moyle. 



(To the Editor of the Annals of Philosophy,) 



SIR, Helston, Jan. 20, 1822. 



In sending the following meteorological journal kept at 

 Helston, Cornwall, for the year 1821, for insertion in your 

 Annals, it will be proper to state the circumstances under which 

 it is formed. It consists of three observations daily, viz. at 

 eight o'clock in the morning, at one at noon, and from ten to 

 eleven o'clock at night, or as near as possible to those hours. 

 The barometrical heights are very correctly made by a sUding 

 index measuring from the surface of the mercury in the reser- 

 voir. The thermometer has a due northern aspect, and is insu- 

 lated from the wall of the house, on which indeed the sun never 

 shines. I give you only the mean of the three daily observa- 

 tions, stating at the foot of each month the maximum and 

 minimum for that month. Where the wind was variable, the 

 most prevailing for the 24 hours is given. 



1 am. Sir, your obedient servant, M. P. Moyle. 



