3. From the same place an ascent was made 5th September, 1862, when at 1h. 48m. p.m. barometer was 11.954, air O deg.; at Wrottesley Hall 29.38, air 56 deg. Height, 23,923 feet. 4. From the Crystal Palace a balloon ascent was made 20th August, 1862. At 6h. 47m. p.m. barometer was 25.55, air 50 deg.5; and at the same time at Greenwich Observatory, at 159 feet above the sea, the barometer was 29.81, air 63 deg. Height, 4,406 feet. 5. From the same place an ascent was made 8th September, 1862. At 5 p.m., the balloon being over Blackheath, barometer was 25.60, and the air 49 deg.5, while at Greenwich, barometer was 29.92, air 66 deg.4. Height, 4,461 feet. CHAPTER V. SECONDARY BAROMETERS. =43. Desirability of Magnifying the Barometer Range.=--The limits within which the ordinary barometric column oscillates, do not exceed four inches for extreme range, while the ordinary range is confined to about two inches; hence it has often been felt that the public utility of the instrument would be greatly enhanced if by any means the scale indications could be increased in length. This object was sought to be obtained by bending the upper part of the tube from the vertical, so that the inches on the scale could be increased in length in proportion to the secant of the angle it made with the vertical. This was called "the diagonal barometer." The upper part of the tube has also been formed into a spiral, and the scale, placed along it, is thus greatly enlarged. But these methods of enlarging the indications cannot be so successfully accomplished, nor so cheaply nor so elegantly, as is done by the principle employed in the dial barometer. Hence they are not in use. [Illustration: Fig. 31.]