INTO THE STRENGTH OF WROUGHT-IRON PLATES. 
697 
Table XII. Strength of riveted Plates. 
No. 
of 
exp. 
Description of plates 
and mode of riveting. 
Weight 
laid on 
in lbs. 
Changes produced by 
weight. 
Breaking 
weight in lbs. 
Form of specimen and 
mode of fracture. 
Remarks. 
43. 
44. 
Plates the same as 
before, their edges 
brought into contact, 
and each plate riveted 
by three rivets f of 
an inch diameter, to a 
plate on each side of 
the joint, each ex- 
ternal plate being half 
the thickness of the 
internal, or a little 
thicker; AB=3iins. 
Plate same as last .. 
19,879 
Sound; no altera- 
tion. 
Pig. 12. 
Q Q 
( 
m 
Q Q 
( 
24,715 
25,723' 
21,355. 
Q Q 
( 
Q Q 
< 
Both side plates were tom across, 
and two of the rivets cut off. The sum 
of the thickness of the side plates was 
■24 inch, the middle plates being "22 
inch thick. 
The middle plates were left sound. 
Second experiment broken as before, 
the two outside plates torn off ; all the 
rest sound. 
45. 
Same asthelastexpe- 
riment, having thicker 
plates outside, each 
being '15 inch thick. 
Fig. 12 o. 
23,371 
Joint good 
24,715 
46. 
47. 
Differing from the 
last only in having five 
rivets to each plate in 
double rows instead of 
three rivets f diame- 
ter; AB=3iinches... 
Same as the last 
23,371 
25,387 
23,371 
24,715 
Joint sound. 
Joint sound 
Slightly altered 
joint good 
26,059 
27,403 
Middle plate torn straight across the 
rivet-holes. 
All the rivets and both plates left 
sound. 
( ) 
Both outside plates torn across at 
the three rivets. 
Outer plate sound ; tom across the 
two rivet-holes. 
Rivets sound; inner plate only torn. 
When the comparative merits of plates and their riveted joints were under consi- 
deration, it appeared desirable to repeat several of the experiments, particularly those 
which seemed to throw light upon their relative powers of resistance. I considered 
these experiments to be of importance, as they increased our knowledge, as respects 
the strength of the material, and also its properties in combination. 
In ship-building these objects are of some value, as any reduction in the powers or 
parts of a vessel by imperfect construction, or misapplied material, might lead to 
serious error and even great risk to the safety of the ship. 
Since the first use of iron for these objects, it has been the practice to countersink 
the heads of the rivets in order to present a smooth surface for the passage of the 
vessel through the water. This practice is in general use at my works at Millwall, 
and I believe the same methods are pursued at the establishment of Messrs. John 
Laird and Co., and others in different parts of the country. The introduction of this 
system of riveting caused a further extension of the experiments, in order to elucidate 
the various forms of joints given in the preceding Tables, and further to investigate 
the strength of the joint with a plate riveted on each side, which appears to be the 
strongest and best calculated to resist a tensile strain. This description of joint is 
seldom used in ship-building, but in order to render the experiments as perfect as 
4 u 
MDCCCL. 
