( 175 ) 
IX. — An Account of a series of TJiermometrical 
Observations, made hourly at Leith, during 
Twenty-four Successive Hours, and once every 
Month, from July 1822 to July 1823, 
By Mr John Coldstream. 
{Read Uth July 18S3.) 
TThE best and most valuable plan for the keeping of a 
thermometrical register, would undoubtedly be, to make 
observations at the end of short and regular intervals ; for 
instance, every hour, or every two hours: because, the 
first and main object of the meteorologist, in keeping such 
registers, being to ascertain the average temperature of 
each day, as nearly as possible, it is evident, he cannot 
fix this point better, than by calculating the mean of very 
frequent observations, which will, of course, always ap- 
proach nearer and nearer to the true average temperature 
of the whole twenty-four hours, in proportion to the num- 
ber of observations. 
However desirable the accomplishment of such a plan 
might be, yet its inconvenience, nay, general impracticabi- 
lity, is abundantly obvious. 
