Steam Engine. 
1. 33 
1551 = 8. 550 
1. 32 
167 = 11.250 
1. 30 
178j = 14. 600 
1. 29 
189i = 18. 800 
1. 27 
2004 = 24. 000 
1. 25 ^ 
212 = 30. 000 
Thus it appears that a ratio having a uniform decrease 
nearly takes place ; and we may therefore extend the table 
of forces at both extremes, without the aid of experi- 
ment, to a considerable distance. Thus assuming the 
ratios for each interval of a 114® below 32° to be, 1.500, 
1.515, 1.530, 1.545, &c. and for each interval above 
212° to be 1.235, 1.220, 1.205, 1.190, 1.175, 1.160, 
1.145, 1.130, &c. we can extend the table many intervals 
of temperature, and determine all the intermediate degrees 
by interpolation. This method may be relied upon as a 
near approximation ; however it does not suj^rcede the 
expediency of determination by experiment; though that 
is much more difficult above 212°, and below 32®, than 
in the intermediate degrees ; because it is difficult to pro- 
cure a steady lieat above 212° ; and below 32* the varia- 
tion of force becomes so small as to elude minute dis- 
crimination. It will appear from what follows that the 
extension of the table by this method above 21^° is in all 
probability accurate, or very nearly so, for 100° or more. 
