HIVES FOR BEE-KEEPERS. 
75 
be made quite -g^n. more to give passage to even an 
under-sized queen. Slats of wood, carefully placed, 
or wires accurately distanced, have for a lengthened 
period been in occasional use to prevent the queen’s 
unwelcome visits ; but the more convenient, and withal 
reliable, form (A, Fig. 24), just now referred to, has 
of late years been extensively employed. It consists 
of sheet zinc, with oblong* perforations about -^in. in 
width, and a full -g-in. in length. This material, used 
as a diaphragm, while no obstacle to the workers, 
should present to the queen an impassable barrier, 
and, doubtless, in all cases would, but from the general 
want of truth in the size of the openings. Several 
specimens the Author has measured give every varia- 
tion between -g^^in. and ^in., and even these limits 
are occasionally exceeded. The result is, that many 
unimpregnated, and a few impregnated, queens may 
escape through it — a considerable practical disad- 
vantage, which has much impeded some experiments 
related under “ Queen Raising,” and which would not 
appear to be unpreventable, since there can be nothing 
in the process of perforating which makes accuracy 
unattainable. Reference to the Figure, showing holes 
(B) that will retain drones but not the queen, or will 
permit all to pass (C), while those in A are of the least 
diameter that will allow a worker to escape, will make 
the necessity of care in this matter the more evident. 
* Mr. O. Poole, many years since, placed ordinary perforated zinc, 
having circular holes, ^vin. in diameter, between his hives and his supers, 
and achieved considerable success; but the French gave us the form now 
universally adopted, by making the perforations oblong (see 
Bee Journal^ June, 1875, page 31 ; August, 1877, page 68; April, 1878, 
page 212). 
