跳转到内容

File:Magdeburg hemispheres small.png

页面内容不支持其他语言。
这个文件来自维基共享资源
维基百科,自由的百科全书

Magdeburg_hemispheres_small.png (245 × 431像素,文件大小:17 KB,MIME类型:image/png


摘要

描述
English: Drawing of a small pair of Magdeburg hemispheres from 1870s, used for demonstrating atmospheric pressure in natural philosophy classes. About 4-5 inches diameter. Magdeburg hemispheres were invented by Otto von Guericke in 1650. To use, the edges of the hemispheres were greased and pressed together, and a vacuum pump was attached to the port at bottom. When the air was evacuated from the inside, the valve at bottom was closed and the pump detached and the hemispheres would be held firmly together by atmospheric pressure. To demonstrate the pressure, ropes would be attached to the ring at top and a ring that could be screwed into the bottom (not shown), and audience members would be invited to try to pull the hemispheres apart. The force holding them together is equal to the area bounded by the circular joint between the hemispheres, multiplied by the difference between the inside and outside air pressure. For 5 inch hemispheres this would be about 280 lb. Alterations to image: removed figure number, increased brightness, and converted JPG to 32 color PNG.
日期
来源 Retrieved 2008-06-27 from Adolphe Ganot & Edmund Atkinson (1872) Natural Philosophy for General Readers and Young Persons, D. Appleton & Co., New York, p.101, fig.90 on Google Books
作者 Adolphe Ganot
授权
(二次使用本文件)
Public domain in USA - first published in USA prior to 1923

许可协议

Public domain
Public domain
这个媒体文件在美国属于公有领域。这适用于版权过期的美国作品,通常因为其首次出版于1929年1月1日之前,或即便当天或以后出版,其并未包含版权通告或获得版权回溯。查看这个页面可以获取到更多的解释。

United States
United States
这个图片在美国以外可能尚未处于公有领域;尤其在对美国作品不适用较短期限法则的国家和地区,如加拿大、中国大陆(不含香港及澳门)、德国、墨西哥和瑞士。创作者和发表年份是关键信息,因此必须提供。参见维基百科:公有领域维基百科:版权信息以获取更多细节。

说明

添加一行文字以描述该文件所表现的内容
Magdeburg hemispheres

此文件中描述的项目

描绘内容

文件历史

点击某个日期/时间查看对应时刻的文件。

日期/时间缩⁠略⁠图大小用户备注
当前2008年6月27日 (五) 17:222008年6月27日 (五) 17:22版本的缩略图245 × 431(17 KB)Chetvorno{{Information |Description={{en|1=Woodcut of a small pair of Wikipedia:Magdeburg hemispheres from 1879s, used for demonstrating atmospheric pressure in natural philosophy classes.}} |Source=Retrieved 2008-06-27 from [http://books.google.com/books?id=s

全域文件用途

以下其他wiki使用此文件: