LOCAL AUTHORITIES AND THEIR DUTIES. 57 



system of ventilation would break down, as is frequently 

 the case where ventilators are used having mechanical 

 movements, or where the expensive processes of steam, water 

 power, or artificial heat is applied to produce an up-draught. 



The application of the Air-Pump Ventilator to the venti- 

 lation of soil pipes, drains, and sewers is one which should be 

 better understood by district surveyors and officers of health. 

 The cost is so small, and the precaution so important to 

 public health, particularly in densely-populated neighbour- 

 hoods, that we hope soon to see some vigorous steps taken 

 for their more general adoption. Our builders are not 

 sufficiently under the control of the local authorities ; but 

 although we move slowly, very slowly, on the road of 

 reform, the time must come when the health of the people 

 will be guarded by more practical and systematic measures. 



If apparatus of a very costly character, and liable to 

 frequent or even occasional disarrangement, were needful to 

 provide us with the means of getting rid of sewer gas, there 

 might be some excuse for the extraordinary neglect of such 

 precautions by our builders. 



Mr. W. Eassie, C.E., author of " Healthy Houses," <kc., <fec., 

 recording his experience of Mr. Boyle's invention, says : 

 "I have often made use of the Air-Pump Ventilator for 

 soil pipes, and consider it most admirable. Its action is 

 continuous, and it cannot possibly get out of order. It is 



