56 PROF. GRANT AND PROF. RANKIN. 



In response to this appeal Mr. Boyle received within the space 

 of six weeks testimonials of the most valuable nature from 

 nearly one-fourth of the architectural profession in the United 

 Kingdom, and in this voluminous list are to be found the 

 names of almost every leading architect in the country. 



Professor Grant, Glasgow University, says of the Air- 

 Pump Ventilator : " It is constructed on sound scientific 

 principles. Acts in strict accordance with the laws of 

 nature, and cannot fail to operate." 



The late Professor Macquorn Rankin, Professor of 

 Engineering, Glasgow University, has given his report to 

 the effect that "There is no time throughout the whole 

 year but when there is a sufficient movement of the air at 

 the level of the house tops to cause the Air-Pump Ventilator 

 to act." No higher authority on engineering could be 

 quoted than Professor Rankin, and the opinion expressed 

 being the result of actual personal experiment, we feel 

 justified in accepting it as conclusive. 



Thus far we may award to Robert Boyle and his son the 

 full measure of credit for having settled a very important 

 question, and we may be satisfied with the fact that, for all 

 ordinary purposes, the problem of extracting foul air from 

 buildings has been reduced to the most simple, economical, 

 and reliable form. We say reliable, because if this ventilator 

 could not be relied upon for constant action, the whole 



