250 
On the Strength of Tied Beams. 
[Abo. 
lbs. 
inches. 
154 
,4 
206 
,7 
258 
1,0 
310 
1,4 
862 
1,8 
424 
2,65 
One of the bolts of the chain broke with the last weight ; nearly all of them ap- 
peared bent by the strain, so much so. as considerably to increase the length of the 
chain, and thus deprive the beam of its support; otherwise no doubt it would 
have borne nearly, if not quite, 200 lbs. additional weight. 
No. 2. Another saul specimen, inches square, and 6$ feet long, prepared as 
a model of a 52 feet beam, 12 inches scantling, scale £th of the full size, gave, 
without iron, the following deflections : 
50 lbs. ,6 inches. 
108 1,4 
would have broken with about 415 lbs. 
1st. A flat bar of iron 14 X £ inches was then fitted on, doubled round the 
ends, secured by small iron straps, and supported as above, by three small blocks 
of wood {b bb) between the beam and iron bar. (Fig. 1.) The following deflec- 
tions were now observed. 
2 
Oommwomt .Lith c yrrss. 
lbs. 
143 
400 
700 
1000 
1350 
1400 
1457 
inches. 
,15 
>5 
,95 
1,375 
2,0 
2,2 
2,4 
Th It l lolo 3,0 
StnosTwl3f i U1 ? M? 11 to iucrease so rapidly, that the blocks of wood 
order that thev m °,f 1 ieir > a , Ces ; tIie specimen was, therefore, taken down, in 
y ight be projerly secured by 2 small straps (a a) passing tight- 
