Iron . 251 
breadth 16, side walls 8 feet, with a pavilion roof of die 
common range. 
The work performed here was the filling of about 15© 
pairs of moulds, of all sizes, three times each day* These 
occupied the floor of brick in different ranges, and pre 
sented a very large aggregate of heated surface when pour- 
ed* The quantity of metal thus formed into shot at each 
cast was nearly a ton. In May 1796 the average tempe- 
rature of this workshop for several days during casting 
was IIS' 0 Fahr. One day a spirit-of-wine thermometer 
burst in my hand with a report like a pistol. Its greatest 
range of scale was 120^* the passages betwixt the 
moulds, for the movements of the pourers, were 13Q°„ 
In all these extra temperatures I uniformly observed that 
a considerable portion of the shot, particularly in the third 
cast, passed the gauge with difficulty^, and many of these 
found unserviceable for carronades^ where the windage al- 
lowed upon the calibre of the piece is less. In the middle 
of August in the same year, during a period of very hot 
close weather, I made repeated trials, and found the effects 
always proportioned to the temperature of the workshop*, 
I shall finish this paper with the particulars of one day’s 
observations. 
Temp, of Room* 
1st Cast, 9 in the morning - - 65® 
in 5 minutes of casting rose to 8© 
in 10 to 112 
in 15 to 128 
in 20 to 140 
Greatest heat in 35 minutes being three 
minutes after the pouring had ceased, 156 
From 128 to 156° I felt a sensation of cold similar to 
that when approaching a fire in winter, accompanied by a 
considerable degree of shivering. About 150° this sen- 
sation wore offj and I felt comparatively comfortable. Per- 
