894 
ME. HODG-KINSON’S EXPEEIMEXTAL EESEAECHES 
as a pillar ; and indeed less than half the strength of a hollow cylindrical pillar of the 
same weight and length, rounded at the ends. 
Comparing the results of the cylindrical pillars tried, it appears that those of the 
second quality, or No. 2, are usually weaker than those of No. 1 of the same iron. In 
the irons below we have the breaking weights of pOlars, 10 feet long and 2 ^ inches 
diameter, of the first and second quality, as follow : — 
lbs. 
Old Park Iron, No. 1 . . 66086 
Calder Iron, No. 1 . . . 60677 
Coltness Iron, No. 1 . . 52680 
lbs. 
No. 2, or second quality . 
. 55032 
No. 2, or second quahty . 
. 55032 
No. 2, or second quality . 
. 50328 
The properties of the irons of the second quality are deduced from the following Table 
of experiments ; those of irons termed No. 1 may be obtained from the second summary' 
of results, page 871. 
Table IX. 
Cast-iron pillars of the quality No. 2, supplied by Messrs. Kvston and Amos, October 
and November 1857. The pillars were cast to be 2^ inches diameter, and each was cut 
10 feet long, the ends being turned fiat and parallel. 
Experiment 1. 
Cylindrical PiUar, Coltness Iron, No. 2. 
Mean diameter from eight admeasurements 2 '494 inches. 
Weight of Pillar 150 lbs. 
^hts laid on. 
Deflections. 
Decrements of length. 
lbs. 
inch. 
inch. 
20693 
T7 
•057 
25397 
•20 
•078 
30101 
•24 
•091 
34805 
•31 
•105 
39509 
•42 
•120 
44213 
•62 
•135 
48917 
•98 
•163 
50328 Broke with this 
in two places near 
the middle. 
As the weights of the following pillars diflered generally but little from that above, 
and a leading object being to compare the results together, the breaking weight has 
been reduced, as before mentioned, in each case, to what it would have been for a pillar 
weighing exactly 150 lbs. 
