174. ENQUIRY INTO THE STRENGTH AND 
imperfect knowledge of the person who attends 
the furnace: on some future occasion I may, 
however, make this a distinct subject of enquiry. 
During the prosecution of the following expe- 
riments, I have been favoured with the assist- 
ance of Mr. Hodgkinson, to whom I am in- 
debted for the calculations and many valuable 
suggestions; also to one of my own pupils, Mr. 
J. Patchett, who rendered valuable assistance. 
Before exhibiting the experiments, I would 
here observe that they were made on quadran- 
gular bars, one inch, and one inch and a half, 
square. These bars were loaded with weights 
suspended from the middle, and supported, first, 
on props 4 feet 6 in. asunder, and afterwards, 
their fractured halves, on supports 2 feet 3 in. 
asunder; the bars thus placed were loaded with 
weights, commencing, in the first series (4 feet 6 
in.) with 14 Ibs.; and generally increasing in the 
ratio of that weight until the bar was broken.* 
This method was adopted in all the experiments, 
and conducted with such care as to ensure 
correct results. 
*In the 2ft. 3in. bars, 28lbs. was not considered too great an 
increase. 
