Cyanide Gas Remedy i'or Scale Insects. 



m 



" 10 oz." or " 8 oz.," to the linear yard in this narrow width. The 

 Division of Entomology (Box 513, Pretoria) would he pleased to advise 

 prospective fumigators on the comparative merits of different samples 

 of duck on which they have received quotations. 



Sizes of Fumigation Sheets. — It has become customary in South 

 Africa to call fumigation sheets by the gross length and width of 

 the cloth. Thus a " 48-foot sheet '" is made of eight 72-inch widths 

 of duck, tlie full length ones of whnli are cut 48 feet long The exact 

 number of yards of T2-inch duck, without any allowance for waste, 

 needed for sheets of the common sizes is as follows : 24 feet size, 



Fl(i. ^.~(Tf negating T>.m«/.— 'I'ypi' conimrmly used in Calilnriiia. Cover i>s of fast- 

 iron and has a raised jjad of rubber at the front where it rests on the edge 

 of the jar, thus leavinjj,' tlie space through which the gas escapes. Similar 

 earthenware jars are made to order in South Africa. ))ut covers have to be 

 improvised or specially inipoftcd. 



26| vards; 27 feet, 34 yards; 30 iect. \il vards; 33 fe^t, 50| vai'ds; 

 36 feet, 60 vards; 42 feet, 82 yards; 48 feet, lOOg yards; 54 feet. 

 135 yards; 60 feet, 166 yards; 66 feet, 200 yards; 72 feet, 240 yards. 

 The size of a sheet jiecessary for a tree depends, of course, on the 

 width of the tiee as well as its height, but a sheet is usually large 

 enough for an oiange tree one-third as higJi as its so-callsd size. Thus 

 a 48-foot sheet may be reckoned large enough for any ordinary 

 orange tree 16 feet high. It would do for many 17 to 18 feet high. 

 The charge for making fumigation sheets varies from maker to maker, 

 but may be roughly calculaied as 4d. per stjuare yarvl of cloth, or 

 8d. per yard for the yardage given above. Ten-ounce duck at the 

 time of writing costs about 10s. 6fl. to 12s. i)ei- 72-inch yard. 



Makers of Fuviif/ation Covers. — Owing tt> the small demand for 

 fumigation covers in South Africa, no one lirin gets much experience 

 in making them. The (iourock I'opework PiXport Co., of Port Eliza- 

 beth, probably supplies as many as any hrm. This company has 

 branches at Capetown, JohanncNbuig. and other centres. Other 

 firms who have long made some cover.s or who are known to have 

 quoted relatively reasonably are: V. 8. Simpson, Church Street, 

 Pretoria; Alex. Cameron c*c Co., Looj) Street, Capetown; M.E. Stores. 



