202 REPORT—1840. 
The foregoing experiments show that there is little difference in the 
strength of iron plates, whether drawn in the direction of the fibre or 
across it. Mr. Fairbairn then gave the results of a long series of ex- 
periments on the strength of riveted plates. The same description of 
plates were here used as in the previous experiments ; they were, how- 
ever, made wider than the former plates, in order that they might con- 
tain (after the rivet-holes were punched out) the same area of cross 
section as the previous ones. 
Mean breaking weights in Ibs. from four plates of equal section, 
riveted by a single row of rivets :— 
20,127 
16,107 
18,982 
19,147 
The mean breaking weights in lbs. from four plates of equal sections 
to the last, but united with a double row of rivets :— 
22,699 
23,371 
20,059 
22,902 
Whence the strength of single to double riveting is as 18,590: 22,258. 
But from a comparison of the results taken from the whole experiments, 
the strength derived from the double riveted joints was to that of the 
single as 25,030: 18,591, or as 1000 to 742. Comparing the strength 
of plates alone with that of double and single riveted joints, Mr. Fair- 
bairn gave their relative values as under :-— 
Mean 18,590 lbs. 
Mean 22,258 lbs. 
For the strength of the plate.........sceeseceeeeres 100 
For that of double riveted joints .........++. secen = nti 
And for the single riveted joints .........+++...0+ 56 
Hence the strength of plates to that of the joints as the respective 
numbers 100, 70 and 56. Mr. Fairbairn then gave a table containing 
the dimensions and distances of rivets for joining together different 
thicknesses of plates. 
Experimental Researches into the Strength of Pillars of Cast Iron, and 
other Materials*. By Eaton Honexinson, Esq. 
When it is considered to what extent pillars of iron and of timber 
are used for the support of buildings, and reflect that there are no 
satisfactory rules by which to measure the strength of pillars, it will 
appear to be a matter of great importance to obtain rules by means of 
experiment, and, if possible, the laws on which they depend. 
A feeling of this kind, heightened by the remarks of Dr. Robison, 
in his Mechanical Philosophy, vol.i., and the strongly-expressed opi- 
nion of our want of such knowledge by Mr. Barlow, led me to wish to 
undertake the inquiry. I mentioned the matter, therefore, to my friend 
* This communication is an abstract of a paper read before the Royal 
Society a short time previous to the meeting. 
