THE PENRYN CRUSADE 97 



as quickly as oil. It has the additional disadvantage 

 of being poisonous. In the oiling methods a knapsack 

 spray pump having a capacity of live gallons was used. 

 The oil applied varied, the following being used : 

 stove distillate, either straight or mixed with crude 

 oil, and water white, straight or mixed with crude oil. 

 The oiling kills all the wrigglers and tumblers within 

 fifteen minutes. Nicotine sulphate does not kill all the 

 wrigglers and tumblers in less than five hours. 



To properly protect Penryn by oiling methods would 

 require an annual expense of about ^oo. 1 This would 

 be a constant expense, and if for any reason the con- 

 trol were discontinued, conditions would soon relapse 

 into a state as bad as previous to the beginning of 

 control. The cost of permanent improvement work 

 would be slight as compared with the benefits obtained 

 (Professor Herms has estimated it at about #200 per 

 square mile for a tract of ten square miles), and the results 

 would be maintained in effective condition with but 

 a slight annual expense. It is more effective, better 

 and cheaper in the end to install permanent work and 

 provide for the slight annual expense of maintenance. 

 Owing to the uncertainty of the popular subscription 

 method, permanent work over a large area cannot be 

 done in a businesslike manner, and therefore such 

 work should be put on a basis of taxation of the people 

 benefited. It is possible for the Board of Supervisors 



1 The reader's attention is called to later estimates given on another page 

 of this book. 



