1867.] Mechanical Science. 595 



some attention in Section Gr. Mr. Mitchell's new plan is to lay- 

 down a bed of three inches of cement-concrete to the required 

 convexity of the street, and then to build on this bed a layer of 

 paving-stones five inches deep and three inches wide, filling up 

 the joints with cement-grout. As tested in Inverness and on 

 George IV. Bridge, Edinburgh, this new system has proved so 

 successful that many advantages are claimed for it as regards dura- 

 bility, cleanliness, repairs, &c. Mr. Mitchell recommends the best 

 Portland cement for the concrete. 



" An Iron Camb for Power-Looms " was the subject of a paper 

 by Mr. James K. Caird, of Dundee. One was read by Sir Edward 

 Belcher on " The Methods for Testing the Speed of Vessels over 

 the Measured Mile ; M another, by Mr. J. E. Napier and Professor 

 Kankine, discussed " The Use of Movable Seats for Slide- Valves ;" 

 and one by Mr. Lewis, of Dublin, had for its subject " An Improved 

 Marine Steam Boiler." Mr. S. J. Mackie also read a long and 

 elaborate paper on " Iron Floating Forts, Iron Harbours, and other 

 Floating Structures, and on Daft's Method of Construction of Iron 

 Fabrics." Other papers of more or less interest followed, and there 

 were also two of a mechanical character read in Section F, because 

 they were considered to be of an economic or statistical character : 

 their subjects were " The Engineering Trade of Dundee," and " The 

 Iron Shipbuilding of Dundee.". 



