On the results of chilling copper-tin alloys

In the Third Report of the Alloys Research Committee, published in 1895, Sir W. Roberts-Austen gives an appendix, by Dr. Stansfield, containing an extremely interesting series of cooling curves of the copper-tin alloys. These curves made it evident that for many percentage compositions there were three or even four halts in the cooling due-to separate evolutions of heat, and that some of these changes must have occurred when the metal was solid. A freezing-point curve was also deduced from the cooling curves. The report contained interesting remarks on the meaning of the curves, but a satisfactory explanation was not at that time possible. In June, 1895, Professor H. Le Chatelier also published a freezing-point curve, giving the upper points only. These two curves agree in locating a singular point near the composition Cu4 Sn, but do not give any singular point nearer to the copper end of the curve.