Mr. Mageough's Method of mounting Thermometers. 365 



object of this communication, which is to illustrate a small 

 portion of a district, that in the circle of a few miles (taking the 

 large clay-deposit of Bovey-heath as a centre) is perhaps, in a 

 geological point of view, one of the most interesting districts in 

 the kingdom. And I propose (in conjunction with J. G. Croker, 

 Esq. of Bovey X race y? wno nas f° r many years paid great 

 local attention to the subject), if consistent with the plan of 

 your Journal, to make it the medium of two or three commu- 

 nications (accompanied by sections, &c), pointing out carefully 

 the different strata, their extent and junction, and the lodes, 

 as far as explored, that occur in them. To this gentleman, as 

 well as to Mr. Petherick the superintendent of the iron-mine, 

 I am indebted for much valuable assistance in drawing up the 

 present paper. I remain, Gentlemen, 



Your most obedient servant, 

 Ilsington, Devon, April 9, 1828. J. T. Kingston. 



LVIII. Account of a new Method of mounting Thermometers. 

 By Mr. W. Mageough. 



To the Editors of the Philosophical Magazine and Annals. 

 Gentlemen, 

 T I ''HE following is an account of a method of mounting the 

 -*• thermometer-tube, in order to make it applicable to pur- 

 poses for which, as fltted-up at present, it could not be used. 



This method has not, that I know o£ been hitherto prac- 

 tised in making thermometers ; but about two years since, the 

 same principle was successfully applied to barometers. 



Mounted in this manner, the tube may be made of earthen- 

 ware or metal, as well as of glass ; it may contain metals or 

 other substances which will expand by heat; and by a little 

 management be introduced into, and made to indicate degrees 

 of temperature, that would speedily destroy thermometers of 

 the ordinary construction. The present account relates only 

 to tubes of glass, such as are generally used for making ther- 

 mometers, without any other condition, than that the size be 

 adapted to the purpose proposed to be effected by the instru- 

 ment. If large enough, it will move with sufficient force to give 

 notice when the apartment where it is placed attains a given 

 temperature, by touching a light lever connected with the sort 

 of alarum-machinery often put into the cheapest clocks. Or, a 

 prepared paper maybe made to pass over a hair-pencil, charged 

 with a liquid not liable to dry or freeze, which pencil, by means 

 of a simple addition to the hour-movement of a common clock, 



will 



