18 Dr Brewster on the Register of the Thermometer kept 



Aiit. V. — Results of the Thermometr'ical Observations made 

 at Leith Fort, every Hour of the Day and Night, during 

 the whole qf the Years 1824 and 1825. By David Brewster, 

 LL. D. F. R. S. Lond. & Sec. R. S. Ed. Corresponding 

 Member of the Academy of Sciences of Paris, &c. * 



In the year 1820, I had occasion to suggest to the Royal So" 

 ciety the propriety of establishing registers of the thermo- 

 meter in various parts of Scotland. 



In a country embracing so many varieties of soil, climate, 

 and elevation, and extending over nearly six degrees of lati- 

 tude, it was an object worthy of a public body to determine 

 the law of the distribution of temperature, even if such a sub- 

 ject had not possessed a separate interest in relation to the 

 horticulture and agriculture of the country. The society did 

 not hesitate in adopting this suggestion ; and many intelligent 

 individuals were found, who undertook to observe the ther- 

 mometer twice a-day, and to measure occasionally the tem- 

 perature of springs and wells. During the first year, viz. 

 1821, nearly sixty Meteorological Journals were regularly kept 

 in different parts of Scotland. The number diminished con- 

 siderably in subsequent years ; but, notwithstanding this di- 

 minution, there is now in our possession a rich series of obser- 

 vations during five complete years, the results of which are 

 nearly ready to be submitted to the Society. 



In directing these observations, it became necessary to se- 

 lect two hours of the day most convenient for marking the 

 state of the thermometer, and the mean temperature of which 

 approached nearest to die mean temperature of the day. 

 The hours adopted were 1U o'clock a. m., and 10 p. m., 

 which had been previously recommended by the Reverend 

 Mr Gordon. The observations were accordingly made at 

 these hours, during three years; but it appeared to me, upon 

 a more attentive consideration of the subject, that the ther- 

 mometer should be observed at the two times of the day at 



* The following paper is a brief abstract of the original memoir read to 

 the Royal Society of Edinburgh on the 23d January 1826, which is illus- 

 trated with five Plates, and will appear in vol. x. Part ii. of 'the Edinburgh 

 Transactions. 



