THE FLY-DIRECTORY 57 



soon compile a fly-directory. Incidentally they will 

 learn more about the sanitary conditions of the several 

 wards or districts than they knew before. A fly- 

 campaign therefore has other results besides the re- 

 duction of flies. It is productive of a more intimate 

 knowledge of local conditions ; insanitary workshops, 

 backyards, lavatories, wash-houses, cowsheds, pig- 

 sties, factories, etc. will come to light, and under the 

 control of the sanitary authority. There can be no 

 better sanitary measure than this. 



