230 Mr. Thompson’s Experiments 
1778, at Stoneland Lodge, a country feat of Lord george 
Germain’s, and I was alfifted by the reverend Mr. bale, 
redor of Withyham, who lives in the neighbourhood. 
The weather proved remarkably favourable for our experi- 
ments, being fettled and ferene, fo that the courfe of them was 
never interrupted for a whole day by rain or by any accident. 
The mercury in the barometer flood in general pretty high, 
and the temperature of the atmofphere was very equal, and 
moderately warm for the feafon. In order that each experiment 
might, as nearly as poflible, be under fimilar circumftances, they 
were all made between the hours of ten in the morning and 
five in the afternoon : and after each difcharge the piece was 
wiped out with tow till all the infide of the bore was perfectly 
clean, and as bright as if it had juft come out of the hands of 
the maker ; and great care was taken to allow fuch a fpace of 
time to elapfe between the firings, as might render the heat of 
the piece nearly the fame in every experiment. 
A defcription of the apparatus . 
The barrel principally ufed in thefe experiments was made 
by wogdon, one of the moft famous gunfmiths in London ; 
and nothing can exceed the accuracy with which it is bored, or 
the finenefs of the polilh on the infide. It is made of the very 
beft iron, and, agreeably to Mr. robins’s advice, I took care 
to have it well fortified in every part, that there might be no 
danger of its burfting. Its weight and dimenfions may be feen 
in the table of the weight and dimenfions of the apparatus* 
p. 242. 
Fig. 1. Reprefents a longitudinal fe£tion of a part of the 
barrel, with the apparatus firft madeufe of for Ihifting the vent 
from one part of the chamber to another, or rather for moving 
the 
