422 Dr BARNES'S Remarks on, and Tabular Results of, 



sudden variation, so as to have much influence on the instru- 

 ment, though Mr PITT, I have reason to know, always made the 

 necessary corrections for the capacity of the cistern and the tem- 

 perature of the mercury. 



During the first six or eight years of these journals (for I 

 have not been able to ascertain the exact period), the hours of 

 registering the thermometer and barometer, in the winter months, 

 viz. January, February, March, November, and December, were 

 8 o'clock in the morning, 1 at noon, and 10 at night. In the 

 summer months, viz. April, May, June, July, August, September, 

 and October, half-past 7, morning; half-past 1, noon; and half- 

 past 10, night. Since then, the observations of the thermometer 

 and barometer were made three times in the day, viz. at 8 o'clock 

 A.M., 1 o'clock P. M., and at 9 o'clock P.M. These hours are per- 

 haps not the best adapted to obtain the mean temperature and 

 pressure of the atmosphere of a day, month, or year, nor is the 

 form of the register the best calculated to elicit all the advan- 

 tages of meteorological observations ; yet a register containing 

 three daily observations, regularly continued for twenty-four years, 

 without the omission of a single day, or even a single observa- 

 tion, it is hoped, will not be found destitute of interest. It must 

 afford a near approximation to the monthly and annual means, 

 and will give pretty correctly the character of the climate and 

 weather of Carlisle. 



The Rain-gauge is a copper vessel, and consists of a funnel 

 inserted into a tube, with a narrow communication, to prevent 

 evaporation. The cylinder is four inches diameter, and the area 

 of the funnel is ten times that of the cylinder, consequently, 

 when there is ten inches of rain in the cylinder, it is one inch of 

 surface. The rain-gauge stands in an open situation upon the gar- 

 den-wall, about twelve feet above the surrounding ground. The 

 water in the gauge, as appears from the registers, was not mea- 

 sured at regular periods. He measured it more frequently, when 

 he thought it was likely to suffer diminution by evaporation. 



