Project Gutenberg 2023-09-15 Public domain in the USA. 139 Hubble, Edwin 1889 1953 Hubble, Edwin Powell 20002512 Photographic investigations of faint nebulae $aChicago :$bThe University of Chicago Press, $c1920. Publications of the Yerkes Observatory, volume IV part II Charlene Taylor, Bryan Ness and the Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive/American Libraries.) "Photographic Investigations of Faint Nebulae" by Edwin H. Hubble is a scientific publication written in the early 20th century. The work focuses on the methodical study of nebulae using photographic techniques, aiming to catalog and analyze these faint celestial objects that lie beyond our solar system. Hubble explores 512 previously uncatalogued nebulous objects organized into clusters, highlighting the significance of photographic plates in astronomy. The opening of the book presents an introduction to the study of nebulae, emphasizing the evolution of observation techniques from visual to photographic methods, demonstrating their inherent advantages. Hubble discusses the current state of knowledge regarding the nature and classification of new nebulae, noting that approximately 17,000 have been catalogued, with estimates suggesting many more await discovery. He outlines the systematic approach taken during his observations at Yerkes Observatory and mentions the classification system used for cataloging these celestial wonders while indicating the inherent challenges posed by measuring faint objects in the night sky. This sets the stage for a detailed exploration of the findings in the subsequent sections of the work. (This is an automatically generated summary.) 20080731103905hubble 1920 US Reading ease score: 94.6 (5th grade). Very easy to read. en Nebulae QB Text Category: Science - Physics 217950 2025-06-28T10:03:47.627434 text/html 243096 2023-09-15T02:05:29 text/html 617371 2025-06-28T10:03:53.768335 application/epub+zip 617288 2025-06-28T10:03:48.971387 application/epub+zip 112200 2025-06-28T10:03:48.291364 application/epub+zip 675408 2025-06-28T10:03:56.448316 application/x-mobipocket-ebook 665364 2025-06-28T10:03:53.195298 application/x-mobipocket-ebook 99890 2025-06-28T10:03:46.741422 text/plain; charset=us-ascii 99938 2023-09-15T02:05:29 text/plain; charset=us-ascii 16613 2025-06-28T10:03:56.599289 application/rdf+xml 6920 2025-06-28T10:03:48.478384 image/jpeg 1582 2025-06-28T10:03:48.384359 image/jpeg 555590 2023-09-15T02:05:29 application/octet-stream application/zip 626954 2025-06-28T10:03:47.660399 application/octet-stream application/zip Archives containing the RDF files for *all* our books can be downloaded at https://book.klll.cc/wiki/Gutenberg:Feeds#The_Complete_Project_Gutenberg_Catalog en.wikipedia