IMl'oKTAXT FLIES 



1011 



First necessary step in health conservation, lluj most sig- 

 nificant fact in the situation is that only l»y cliniinating tin- 

 fly can we form any notion of liow imuli present sickness it 

 On this account Jicahli olhccrs ex cin w Ihmc arc 



is causui<j^. 



Tho tiguie may I't." si\j>j«>sf(l to 

 H'present a imxlt-l 12 iiichos widt-. 

 12 inches tall, ami 10 inches thifk 

 — a cunvenient siz.e for onlinaiy 

 use in a city yard. The speciti- 

 cations will then be r two i-nd 

 boards A inch or \ inch thick, 

 12x10 inches ; four strips for the 

 top frame, Ix A inch, two I'i inches 

 and two 9 inches lonjj; ; wire for 

 top frame, 10x12 inches (raw 

 edyes folded over ^ incli); two 

 top shoulder strij>s IxA inch, 11 

 inches long; four bottom strips 

 \ inch thick ami 12 inches lon^r, 

 two \ inch wide and two 1 inch 

 wide ; screen wire for sides ami 

 bottom in one piece, 12 inclies 

 wide and 41 inches lt)ng (allow 

 1 inch to fold over raw ends, 

 .', inch each) 



roSgy:'aarr QA ^/;^.<M??ift- 



FiG. 54. Cross section aii<l detail of siiil)lt'-\vin(lo\v or barnyard tiytrap 



These traps may be of any convenient si/e, to suit conditions, and may be made 

 of box boards. stri])s. and screen wire. It is well to plan to use wire of stamlapl 

 widths. If used on the liround. the traps may l»e made witliout the tra|>-foIds in 

 the sides, which do most of tlie catchini; wIumi the trap is set in a stable wimlow . 

 P'old the wire squarely at the ani^U's indicated in the tiirure, .1, />'. ' ', /'. A". /■', '/. and 

 at these ixtints sinp iii ■> indi. Fold the i-indi Haps to a rii;ht ani:le, tiirninir tin-ni 

 in directions indicated by small hooks aloim the c<uirse of the win* (dotted line). 

 This allows the bottom rid^e and tlie trap-folds to drop smoothly inside the end 

 boards, and the Haps are tacdved to the end boarils to help bold the wire in plaee 

 and make the trap absolutely tly ti^lit so far as any i-racks aloiii: tin' ••orners are 

 concerned. The holes in the wire are pum-lu'<l by i)Ushin;L: ten 4o-j)cnny w ire spikes 

 thron<;h the exact apex of the bottom ridue. abcuit 1 inch apart. If j:«mmI bait JH 

 ttsed, the dies may become much crowded here. (This must i>e a sharp ".><>' aniud"'. 

 not a rounded dome, or the tlii'S will not tind the holes.) Three holes are snfb- 

 eient for the side folds. Pnneli all these holes after tin' wire is tacked in jdare. 

 The traj) is really as simple as a box. With proper fools a boy ouixlit to <-ut out the 

 end boards, rip Out the strijis, nail up. fold, and tack the wire, all in :il>ont one 

 hour. The main feature of the trap is the {-inch crack opeidnj,' iijnranl to tin* bait 



sayino-, in eft'cct, "Clear tlic air of tiiis universal distrilmlor 

 of filth, in order that we may he ahle to trace (dhcr uays of dis- 

 ease infection." Thus cxtci luination **( llics cdnies to la- tin* 

 necessary first step toward the effective prevention of disea.se. 



