Note 26 — Self-Registering Systems

Report of the 13th Meeting of the British Association for the Advancement of Science, 1843, 1844, p. xi ff. I have found no other reference to this instrument. Considerable attention was given to the thermometer, however, for Wheatstone proposed to send it aloft in a balloon for the measurement of temperatures at high altitudes. A small clock caused a vertical rack to ascend and descend once in six minutes. The rack carried a platinum wire which moved within the thermometer over 28 degrees. From a galvanic battery and a galvanometer on the ground two insulated copper wires were to extend to the balloon, one connected to the mercury and the other to the clock frame. The deflection of the galvanometer was to be timed with a second clock on the ground. (Professor Wheatstone, "Report on the Electro-Magnetic Meteorological Register," Mechanics' Magazine, London, 1843, vol. 39, p. 204).