194 
BEES AND BEE-KEEPING. 
The lower bottom rail follows, being inserted (prefer- 
ably with a touch of glue) into the side-bar notches. 
The foundation is now placed in position, its upper 
edge covering the half top bar, the upper face of 
which is exactly level with the face of the foundation 
rest. The second half top bar is next pressed on, 
so as to grip the foundation. To assist in this, the 
marked and proximate faces of the two pieces are a 
little convex. Adding the second bottom rail com- 
pletes the whole, and lifting the block to the perpen- 
dicular, turning the buttons, and removing the frame, 
with its fixed sheet of foundation, is the work of a 
moment ; and I find, after a number of trials, that the 
whole operation of building-up and fixing foundation 
occupies about half a minute. 
Two practically essential questions at once suggest 
themselves : Is the foundation firmly held ? and is 
the frame thus pushed together sufficiently solid 
for work? The result of experiment is far more 
to the purpose than a statement of opinion. Two 
sheets were tested. The first remained unmoved 
till the strain reached iqlb. ; it then broke, part 
being left in the cleft: the second, at 151b. parted 
at the side, some portion being withdrawn, and 
some left in the cleft. The weight was distributed 
by clamping the sheet. The rigidity of the frame 
is remarkable, and its accurate make prevents any 
trace of winding. The dovetail, also, has great 
holding power. The lighter, invertible standing 
frames (D, Fig. 53) were more easily tested than the 
Standards, and here the dovetails bore an average 
strain of 52lb. before the side bar was broken from its 
