54 THE BEGINNING OF THE ANTI-FLY CAMPAIGN 



fifty thousand inhabitants. Every fly-lair must be 

 marked on the map, and then the cost of dealing with 

 them once every week calculated. This is not a veiy 

 great undertaking, for a man who is experienced soon 

 learns to know where to look for the fly-maggots. A 

 map of the town can be ruled into squares of equal 

 extent, and one man given the work of discovering 

 the fly-lairs in each square. Let him begin at one 

 corner of the square, and examine all the houses, street 

 by street. He should write in a note-book the names 

 of the streets, and the number or name of each house, 

 and if possible the name of the proprietor. The exa- 

 mination should be made at the height of the fly- 

 breeding season. In this way the exact number of 

 fly-lairs can be discovered, and then the cost of dealing 

 with them once every week estimated. This method 

 of making the estimate is really not a very great 

 undertaking, as stated before, and there is the satis- 

 faction of knowing that it is correct, and that there 

 will be little likelihood of the necessity for subsequent 

 requests for further monetary grants ; constant demands 

 for supplementary credits are always a source of annoy- 

 ance to administrators and councils. If necessary, the 

 cost of dealing with the flies throughout the town once 

 every week can be borne by the sanitary authority ; 

 in this case the cost of the labour required can be 

 estimated as well as the extra expense of destroying 

 the fly-larvae, the supply of paraffin or chloride of lime, 

 and any other requisites included. But it is better 

 that the owners of fly-lairs should be made, if possible, 

 to deal with their flies themselves, and the sanitary 

 authority should content itself at first with instructing 

 the public; if this instruction fails the sanitary 

 authority can afterwards undertake the work of fly- 



