File:The Adolfo Stahl lectures in astronomy, delivered in San Francisco, California, in 1916-17 and 1917-18, under the auspices of the Astronomical Society of the Pacific (1919) (14784651342).jpg

Identifier: adolfostahllectu00astruoft (find matches)
Title: The Adolfo Stahl lectures in astronomy, delivered in San Francisco, California, in 1916-17 and 1917-18, under the auspices of the Astronomical Society of the Pacific
Year: 1919 (1910s)
Authors: Astronomical Society of the Pacific Aitken, Robert Grant, 1864-1951
Subjects: Astronomy
Publisher: San Francisco Stanford University Press
Contributing Library: Gerstein - University of Toronto
Digitizing Sponsor: MSN

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analyze the more importantfactors contributing to the present state of astronomicaldiscovery, so rich in both quantity and quality, we shall findseveral contributing causes, interdependent, rather thanseparate in their effects. Though it will be of interest tosegregate these, it will be seen at once that it is really possibleto combine all in the one phrase,—better tools. These factorsare: 1. The existence of many large observatories liberally sup-ported by government appropriations or by benefactions,devoted almost exclusively to astronomical research. Thenumber of investigators, and the available instrumental equip-ment, are immeasurably greater than they were half a centuryago. 2. The great advances in mechanical processes which haveenabled the instrument-maker to furnish more accurateinstruments and larger lenses and mirrors; here we mustinclude the work of the engineer in providing adequate mount-ings for giant instruments. 3. A tremendous development in the character and power
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PLATE XX\II. The 72-Inch Reflecting Telescope of the Dominion ASIROPHYSICAL OBSERVATORY. Astronomical Discovery 119 of the methods employed, due in large part to the applicationand adaptation of processes perfected in the allied sciences ofphysics and chemistry. 4. Properly to be included under the preceding heading,but so important as to deserve separate mention,—the use ofphotography. Of the above, it is photography, more particularly the per-fection of the modern dry plate, which has most completelyand radically changed the methods of astronomical discovery.Fully three-fourths of all modern astronomical observationsare photographic, and it seems highly probable that the daymay come when practically all astronomical research willdepend upon photographic processes. A better conception ofthe. manifold applications of photography in astronomy maybe derived from the following short summary: PH0T0GR.\PIIY IN OBSERVATIONAL ASTRONOMY Fundamental Astronomy. The determijiation of theabsolu

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