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Transferred from en.wikipedia to Commons by Maksim.

This is a scan of a Pickett pocket slide rule, done by me, Benjamin Crowell, in 2005. The slide rule does not have a copyright notice on it, and works published in the U.S. without a copyright notice before 1977 are in the public domain. I therefore think the slide rule itself is in the public domain under U.S. law. I'm making my scan available under the GFDL license.

已授權您依據自由軟體基金會發行的無固定段落、封面文字和封底文字GNU自由文件授權條款1.2版（不含其他版本），對本檔進行複製、傳播和／或修改。該協議的副本列在GNU自由文件授權條款中。

僅1.2版http://www.gnu.org/licenses/old-licenses/fdl-1.2.htmlGFDL 1.2GNU Free Documentation License 1.2truetrue

原始上傳日誌

Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version.

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• (del) (cur) 19:33, 23 April 2005 . . en:User:Bcrowell Bcrowell ( en:User_talk:Bcrowell Talk) . . 558x152 (20510 bytes) (This is a scan of a Pickett pocket slide rule, done by me, Benjamin Crowell, in 2005. The slide rule does not have a copyright notice on it, and works published in the U.S. without a copyright notice before 1977 are in the public domain. I therefore think)
• (del) (rev) 19:24, 23 April 2005 . . en:User:Bcrowell Bcrowell ( en:User_talk:Bcrowell Talk) . . 634x174 (25206 bytes) (This is a scan of a Pickett pocket slide rule, done by Benjamin Crowell in 2005. The slide rule does not have a copyright notice on it, and works published in the U.S. without a copyright notice before 1977 are in the public domain. I therefore think the )
• (del) (rev) 19:18, 23 April 2005 . . en:User:Bcrowell Bcrowell ( en:User_talk:Bcrowell Talk) . . 652x203 (27548 bytes) (This is a scan of a Pickett pocket slide rule, done by Benjamin Crowell in 2005. The slide rule does not have a copyright notice on it, and works published in the U.S. without a copyright notice before 1977 are in the public domain. I therefore think the )