Meteorological Obfervations. 619, 
APPENDIX. 
(a.) 
COPY OF A LETTER FROM Maz, COPLAND, OF 
DUMFRIES. 
, Drar Sx Re 
I MOST readily feize this opportunity 
to correct the laft obfervations in my letter of 
January 15th. 1793, (fee page 271). The 
ftate of the phenomena appears from farther 
experience to be different from what is there 
expreffed. 
When two rain-gages are kept at different al- 
titudes, and at no great diftance from each other, 
the quantities of water collected by them are 
found alternately to exceed each other on a variety 
of occafions. The loweft of my gages ftands only 
two feet above the ground; the fuperior feven 
feet. In all heavy rains, or when the falls are af 
any duration, the former exceeds the latter at a 
medium of about a twenty-fifth part pf the 
whole quantity in the gage; and in fummer 
this excefs appears to be greater than in winter. 
‘So great an increafe of precipitation in a dif- 
ference of only five feet of altitude in the atmof- 
phere, is a proof that the ftratum or portion 
of air, which is in a precipitating {tate, is 
probably of no great depth: For when allow- 
Hhhhe ance 
