50 
“ A Comparison of Solar Radiation on the Grass, and at 
Six Feet from the Ground/’ by Thomas Mackereth, 
F.RA.S., F.M.S. 
As the Corporation of the Borough of Salford has recently 
erected a structure in front of the Town-Hall for meteor- 
ological purposes, and as no better position could be found 
for the solar radiation thermometer than on the apex of the 
roof of the shade-stand, which is six feet from the ground, 
I fixed a similar thermometer in a similar position at Eccles 
in order that I might institute a comparison of solar radia- 
tion between Eccles and the Borough. Though I antici- 
pated very different results from a thermometer thus placed, 
than I had found from a similar thermometer placed upon the 
grass, I was not prepared to find them so widely different 
as I shall here present them. The instruments used are 
the ordinary exposed black-bulb self-registering thermome- 
ters, duly compared. I have also added a column of com- 
parison from results obtained by a self-registering black- 
bulb thermometer placed in vacuo on the grass. The obser- 
vations are for the month of October only, the only complete 
month in which all the instruments have been used. 
