. Barometers and the measurement of atmospheric pressure. A pamphlet of information respecting the theory and construction of barometers in general. Barometers; Meteorological instruments. 44 It consists of a cylinder A, on which the recording paper is wound, revolving once a week by means of a clockwork contained inside. A series of corrugated metallic shells B, eight in number, joined one above the other and exhausted of air, forms an aneroid system eight times as sensitive as a single chamber. The movement of the shells is still further greatly magnified and is transmitted to the recording
. Barometers and the measurement of atmospheric pressure. A pamphlet of information respecting the theory and construction of barometers in general. Barometers; Meteorological instruments. 44 It consists of a cylinder A, on which the recording paper is wound, revolving once a week by means of a clockwork contained inside. A series of corrugated metallic shells B, eight in number, joined one above the other and exhausted of air, forms an aneroid system eight times as sensitive as a single chamber. The movement of the shells is still further greatly magnified and is transmitted to the recording pen C by a series of connecting levers. The pen may be released from contact with the paper by pushing the lever D to the right. The corrugated shells are the same as used in ordinary aneroids, as described in paragraph 46, the steel springs for distending the shells being placed inside. The shells are made into a vertical column by. Figure 28.—Richfird's aneroid barograph screwing the one on the other. The lower base of the column being fixed, the upper end rises and falls with every variation in the atmos- pheric pressure, by a quantity which is the sum of the displacements of the elementary shells. The compensation for temperature is accomplished by leaving a sufficient quantity of air in one of the shells, ascertained by experi- ment when the instrument is made, so that with a rise of temperature the tendency of the barometer to register too low on account of the weakening of the springs, and the expansion of the levers and other parts, is counteracted by the increased pressure of the air in the shell. However, the instrument should be kept at a uniform temperature as far as Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marvin, Charles F. (Charles Frederick), 1858-1943. Washington, U. S. G
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Keywords: ., bookcentury1900, bookpublisherwashingtonu, booksubjectbarometers
