Surveying and Levelling Instruments, Theoretically and Practically Described. For construction, qualities, selection, preservation, adjustments, and uses; with other apparatus and appliances used by civil engineers and surveyors in the field.

CHAPTER XVIII.

Chapter 1815 wordsPublic domain

MEASUREMENT OF ALTITUDES BY DIFFERENCES OF ATMOSPHERIC PRESSURE:-- Historical Note--Mercurial Barometer--Construction--Operation-- Aneroid Barometer--Construction--Various Improvements--Hypsometer 548