Word: hydrogen
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Dates: during 1900-1909
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...humidity have been measured, but the wind currents are of special interest to aerial navigators. The wind currents differ greatly with the time of day and the height. Observations are made by sending up a rubber balloon which carries a basket containing instruments. As the balloon rises the hydrogen expands it until the balloon bursts, when the instruments fall to the ground. A height of eleven miles has been reached in this manner, a temperature of 111 degrees below zero, and a wind velocity of 101 miles an hour...
...speaker then gave a short history of aeronautics. The first ascension was made in 1783 from Versailles, France, in a hot-air balloon. Animals only were sent up, but when it was found to be safe men attempted an ascension. In the same year hydrogen was used as a lifting power. The next year a balloon was first used for scientific purposes, and about the same time one crossed the English channel from England to France. From then on, numberless ascents have been made, and great heights reached...
...PHYSICAL COLLOQUIUM. "Radio-active Change," Mr. Hodge; "The Secondary Spectrum of Hydrogen," Dr. Lyman. Jefferson Physical Laboratory, Room...
Physical Colloquium. Some Recent Experiments on Sound. Professor Sabine.--The Liquefaction of Hydrogen and Helium. Dr. Morse. Jefferson Physical Laboratory, Room...
Among the more important results of the investigations of the past year is the discovery of two new variables, three stars having peculiar spectra and the presence of hydrogen lines in the spectrum of V. Andromeda. The discovery of the variability of light of Eros has added greatly to the value of the early Photographs of that body. Photographs of the spectrum of lightning were obtained last summer for the first time. It is expected that the discovery will open a new field for spectroscopic work...