230 Minutes of Meetings. 



each piece to the forces applied to it, so that it shall not, by being too 

 large or too heavy, give rise to unnecessary friction ; by the balancing 

 of all moving pieces, so that their inertia shall not cause unnecessary 

 strains, and by proper lubrication. As a novelty with respect to lubri- 

 cation, may be mentioned the use of bitumtjious rNGiTENTS, or mineral 

 grease and oil, which appears to succeed well. 



92. As a recent invention in the mechanism by which power and 

 motion are transmitted, may be mentioned the fhictional geaees'G of 

 Mr. Robertson, in which wheels act upon each other by wedge-formed 

 ridges and grooves, extending round their circumferences, instead of act- 

 ing by means of teeth. This kind of mechanism has the same advantage 

 which belts have, in occasionally permitting the wheels to slide on each 

 other, so as to prevent sudden shocks. 



93. There remains a third point of view from which machines may 

 be considered — that which regards their pueposes, or the kinds of work 

 which they perform. But although we have touched as briefly as 

 possible upon all the preceding divisions of our subject, our Report has 

 already extended .to as great a length as is consistent with the proper 

 limits of a paper to be read before this Society ; and, besides, the full 

 consideration of machines, as regards their furposes^ would embrace the 

 whole range of Arts and Manufactm-es, — a subject not for one, but for 

 many reports, and not for one committee of Engineers, but for several 

 committees, each composed of persons conversant with a particular 

 branch of Arts and Manufactures. Here, therefore, we beg leave to 

 conclude for the present. 



For the Committee, 



W. J. Macquokn Rankes'e, Convener. 



A few additions and alterations have been made in this Report, 

 having reference chiefly to discoveries and improvements which were 

 made in the interval between the time at which it was read (April, 

 185S), and that at which it was printed (November, 1858). 



AprH 21, 1858. — The Peesldent in the Chair. 



Mr. Hastie stated that the Council, at a meeting held yesterday, 

 agreed to concur in a memorial to the Board of Trade from the Meteo- 

 rological Society of Scotland, in favour of a grant of money to that 

 Institution. 



The President announced, that at an extra meeting of the Society 

 to be held on Wednesday, the 28th instant, Mr. Thomas Rose, on the 



