Section G.— MECHANICAL SCIENCE. 

 Peesident of the Section— Edward Easton, Esq., C.E. 



THURSDAY, AUGUST 15, 1878. 



Mr, Easton gave the following Address : — 



At the commencement of each Annual Report it is stated that one of the objects of 

 the British Association is " to give a stronger impulse and a more systematic 

 direction to scientific inquiry," and its division into Sections was made with the 

 view of concentrating such inquiry upon the several departments of Science. 



I propose to endeavour to further that object by making the Address, which I 

 have the honour to deliver as President of Section G, a preface as it were to the 

 fuller consideration of a subject of the highest interest to all the inhabitants of the 

 United Kingdom, and not least to those who have so freely extended their hospitality 

 to us on this occasion. That subject is the Conservancy of Rivers and Streams in 

 the widest sense of the term. 



It is worthy of remark that it was on the occasion of the first visit of the 

 British Association to this city in the year 1835, that the Mechanical Section was 

 virtually instituted. Previous to that meeting the Section of Mathematics and 

 Physics had undertaken the discussion of questions having reference to the prac- 

 tical application of physical science, but at the Dublin meeting a subsection 

 was specially appointed, which in 1836 became Section G. The late Mr. George 

 Rennie, that distinguished son of one of our greatest engineers, presided on the 

 occasion. His report on Hydraulics presented to the Association in 1834 is full 

 of research, and should be studied by every one interested in the question of rivers. 



I am glad to be able to announce that my Address will be followed by a series 

 of Papers on the same subject, the authors of which are certainly very well 

 qualified to elucidate its details ; and I trust that many of the other eminent men 

 who are attending this meeting of the British Association will join in the discussion 

 of these Papers. 



By the Conservancy of Rivers and Streams I mean the treatment and regulation 

 of all the water that falls on these islands from its first arrival in the shape of rain 

 and dew to its final disappearance in the ocean. 



I had at first, in my ignorance, contemplated treating the subject in a still 

 wider manner by referring to the rivers and streams of other countries ; but I soon 

 found that the vast extent of the field to be traversed would make it extremely 

 unlikely that I could, with any satisfactory result, attempt the more restricted task 

 which I have now before me. Indeed, without the promised aid which I have re- 

 ferred to, I should have shrunk from attempting it at all. 



The question of the Conservancy of Rivers and Streams involves the consideration 

 of their regulation for the following principal purposes : — 



1st. For the supply of pure and wholesome water for the domestic and sanitary 

 wants of the population. 



2nd. For the supply of water of proper quality and sufficient quantity for 

 industrial purposes. 



