Alkali. Bleach Acid Machine (chemic). Washes. / Saturate. (1) < \ Steam. / (2) Continuous | (chemic) | machine | (or keir if (2) < for yarns, | etc.). | (2a) Machine or \ pit sour. (3) Wash up for finishing. ORDINARY SYSTEM. Alkali. Bleach. Acid Machine Washes. (1) Lime stew. (1) Wash. (2) Sour. (2) " (3) Gray bowk (3) " (soda ash). (4)I Chemic. (4) " (5) Sour. (5) " (6) White bowk. (6) " (7)II Chemic. (7) " (8) Sour. (8) " It will be understood that 2 and 2a are merged into a single process by using the "continuous" machine. Of course, it will be understood that the cloth has in each case to be cleansed from size and loose impurities. The "Mather-Thompson" Company claim that their system takes twelve hours in the case of "market" or "white" bleaching. They reckon eight hours for the steaming process and four for bleaching and washing. This has to be compared with the old system, which generally takes forty hours, made up as follows: 8 treatments with reagents and the necessary washings, the former taking four hours and the latter one hour each. The "Mather-Thompson" system has created considerable commotion in English bleaching circles. It is generally considered that the bleachers throughout the whole country will be compelled to adopt it, so great is the saving in time and cost. In commencing a bleachery, the cost of plant by this system is, I understand, less than by the old processes.--_Textile Colorist_. * * * * * INSTRUMENTS FOR DRAWING CURVES. By Prof. C.W. MacCord, Sc.D. I. THE HYPERBOLA.