594 Meeting of the British Association. [Oct., 



Machinery." It was a most graphic account of the history of his 

 experience, which, in the year 1826, led to the invention. Mr. 

 Fairbairn stated that he had been engaged at the Paris Exhibition 

 to report on reaping machines, and that he had seen 15 or 16 

 machines tried on a large farm, and that the best, an American 

 invention, differed but very little from Mr. Bell's. 



Mr. J. Clerk Maxwell's paper on " The Theory of Diagrams of 

 Forces as applied to Koofs and Bridges," was very theoretical, and 

 had an interest for but a limited number of persons. 



In reference to the Keport of the Committee on the Patent 

 Laws, the President announced that it was not ready, owing to the 

 absence of the members in London and Paris, during July and 

 August, but considerable progress had been made with it, and the 

 Committee was re-appointed. 



A highly important paper was read by Dr. W. Fairbairn on 

 " Experimental Besearches on the Mechanical Properties of Steel in 

 its present improved state of Manufacture." The introduction to 

 the paper gave a condensed history of the improvements lately made 

 in the manufacture of iron and steel, and referred to the attempts 

 to substitute steel for iron in the construction of boilers, bridges, &c, 

 on account of its greater tenacity and security. Dr. Fairbairn dis- 

 courages the placing of too much reliance on steel until the present 

 difficulties of its manufacture are surmounted, and until it can be 

 produced with as much uniform certainty as iron. Time and close 

 observation of facts would overcome the difficulties now experienced. 

 The author's experiments had been specially directed to the deter- 

 mination of the following points : — 1. Transverse Strain. 2. Tensile 

 Strain. 3. Economic use of Material. 4. Compression. 5. Com- 

 parison of Tensile and Compressive Besistances; and they had 

 enabled him to announce many results of the utmost importance. 



One of the very few representatives of American science at 

 Dundee was General Haupt, whose boring and tunnelling machine 

 has recently excited a large amount of attention in this country. 

 The inventor gave a full and elaborate description of his machine, 

 and illustrated it by diagrams. The machines weigh 125 lbs. each, 

 are only 30 inches long, 6 inches wide, and 8 inches high. On the 

 subjects of power by compressed air, ventilation, and use of steam 

 in tunnelling, General Haupt's statements excited much interest, 

 and drew forth very complimentary remarks from Greneral Lefroy, 

 Dr. Fairbairn, and the President, the latter expressing a hope that 

 he would again favour the British Association with his presence. 

 Dr. C Le Neve Foster followed General Haupt with an account 

 of a boring machine used at the Preseberg Mines in Sweden. 



A paper by Mr. Joseph Mitchell, C.E., on " A New Mode of 

 Constructing the Surface of Streets and Thoroughfares," excited 



