THE Institution of Mechanical Engineers held their summer meeting last week, at Edinburgh, under the presidency of Mr. E. H. Carbutt. The meetings were held in the Library Hall of the University, the members being received by the Marquis of Tweeddale, the chairman, Sir William Muir, Principal of the University, and other members of the Reception Committee. The two papers first read on Tuesday related to the Forth Bridge and the machinery employed in its construction. Both papers we reprint to-day. The discussion on the first of them referred mainly to the subjects of expansion and contraction under variations of temperature and to wind-pressure, and in reply the author of the paper, Mr. E. M. Wood, explained that 11/2 inches per 100 feet was allowed for expansion, or double the amount usually thought sufficient; whilst, as regards the wind-pressure, the highest registered had been 351/4 Ibs. per square foot, whilst 56 Ibs. was allowed for. All the speakers who discussed the paper of Mr. Arrol, the contractor for the bridge, referred in high terms to the skill and ingenuity exhibited throughout. Later on in the day the members made an excursion to the Forth Bridge, Mr. Arrol and the heads of the various departments at the works acting as guides. A striking feature was the com-parative noiselessness with which the work was carried on, owing to the successful use of hydraulic power in riveting.