ON STRENGTH AND PROPERTIES OF CAST IRON. 399 
From the above it appears, that a progressive increase, in the 
deflections of the bars, has taken place, since the time they were 
charged, in the ratio of 1000, for the cold blast, to 1303, for the 
hot blast. 
The hot blast bar in these experiments being more deflected 
than the cold blast, indicates that the particles are more extended 
and compressed in the former iron, with the same weight, than 
in the latter. This excess of deflection may in some degree 
account for the rapidity of increase, which it will be observed 
is considerably greater in the hot than in the cold blast bar. 
The next experiment was from the same metal, cast as before 
into rectangular bars 1 inch square, and loaded with additional 
weights, amounting to 336 lbs. on each bar. 
TaBLeE XII. 
Table of deflections as exhibited with permanent weights of 
a 
| EXPERIMENT 1. 
| 
EXPERIMENT 2. 
336 lbs. suspended from the centre of bars of cold and hot 
blast Coed-Talon iron, cast to be one inch square, and left 
to determine the effect produced on each bar after given inter- 
vals of time. 
Distance between the supports 4 ft. 6 in. 
oe 
| : Sa ; s i 
cold Blast Iron No. 2 3 # ||Cold Blast Iron No. 2 
|Breadth of bar, 1020 @ S . ||Breadth of bar, 1°020 
Depth do, —-1"030 E 3 & |[Depth do, —1-040 
_ 
2 ® 5 4 
* os =} oh . Oo: 4 
2/23 Ze 6 =| 2 Ba |e8 at 
S4/58 Fe 5 Bao) > 
AEisaise2 * he qa |oeeg/ee 
a g2/% § BS me - SAIS SE 
Bee \e2 Be is | eal ee 
a) BT 1 oO a &o res) | a 
D ® 3 = o as Ba | os 
o 238 =) S = o 2s /|A = 
E |}85| 8 |issz «182s. er ese | oe 
MME EH ase. || a cveas | abbece BG |)*1601.20... The weight, 336 Ibs., was left 
eeececees | aencee 
seeeee 
seeereces | coeses 
seeessese «=| sencee 
seeeeeses =| seceee 
March 6th 
Do. 9th 
Do. 11th 
Do. 17th 
April 15th 
May 3lst 
Aug. 22nd 
Noy. 18th 
1838 
Jan. 8th | 88 
March 12th! 51 
June 23rd | 78 
seneee | eanses 
permanent on the cold blast bar 
on Friday, March 3rd, at six 
o’clock p.m. The same weight 
(336 lbs.) was fixed stationary 
upon the hot blast bar on Tues- 
day,March7th,at11o’clock,a.m. 
When the weights, 336 lbs. 
were placed on the cold blast 
bars, after the elasticity had 
been taken, the deflection in- 
creased from 1221 to 1°267. 
On the hot blast bar the de- 
flection increased with the re- 
storation of the weights from 
1:374 to 1:397. 
The mean deflection under 
various temperatures is, for 
the cold blast 1-280, increase 
009 ; for the hot blast 1-486, 
increase *024. 
