ANNALS 



OF 



PHILOSOPHY. 



JUNE, 1823. 



Article I. 



A new and east/ Method of ascertaining the Degree of Tempera- 

 ture at which Water is at its Maximum Density. By Mr. 

 James Crichton. 



(To the Editor of the Annals of Philosophy.) 



SIR, Glasgow, May 2, 1S23. 



Having lately been much engaged in determining the specific 

 gravities of certain fluids, by means of adjusted balls of glass, 

 and being satisfied that for simplicity and accuracy, no method 

 whatever is nearly so good ; I was led to think, that another 

 important point could thereby with greater certainty be ascer- 

 tained, than by any mode yet adopted. This is to determine the 

 temperature at which water attains its maximum density. 



Of all who have hitherto attempted to decide this question, 

 whether British or foreign philosophers, no one seems to speak 

 with the precision which might be desirable, of the degree at 

 which the phenomenon takes place. The French say it is 

 between 4 and 5 of Celsius, thus admitting an uncertainty of 

 about 2° of Fahrenheit ; some in our own country think it is at 

 39, while others place it at 40. 



Any person who is aware of the many sources of error, and 

 of the vague nature of the requisite compensations, will not won- 

 der at this indecision ; the difficulty alone, of maintaining an 

 uniform temperature, throughout a large or deep body of water 

 is very considerable ; hence the bulkiuess of the solid used by 

 New Series, voi. v. 2 i» 



