File:Thacher's Calculating Instrument.jpg
Original file (3,635 × 1,813 pixels, file size: 1.62 MB, MIME type: image/jpeg)
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Summary
[edit]DescriptionThacher's Calculating Instrument.jpg |
English: Thacher's Calculating Instrument, patented in 1881, can be thought of as a series of conventional slide rules mounted around the periphery of a cylinder. There are 20 pairs of scales forming the outer framework of the cylinder. Within this framework there is a solid cylinder that can be both rotated and moved longitudinally within the framework of scales. The open framework itself can also be rotated as a unit. Thacher's Calculating Instrument was mounted on a mahogany base and produced by the Keuffel and Esser Company of New York. |
Date | |
Source | Own work |
Author | Gotanero |
About Thacher's Calculating Instrument
[edit]On November 1, 1881 Edwin Thacher, a graduate of Rennselaer Polytechnic Institute, was awarded U.S. Patent #249,117 for an improvement in slide rule technology. Thacher worked as an engineer for the Keystone Bridge Company in Pittsburgh, Pennsylvania where he designed railway bridges. To assist in his calculations, he designed a cylindrical slide rule that had distinct advantages over a conventional slide rule, most notably a much higher degree of accuracy.
Thacher's Calculating Instrument can be thought of as a series of conventional slide rules mounted around the periphery of a cylinder. There are 20 pairs of scales forming the outer framework of the cylinder. Within this framework there is a solid cylinder that can be both rotated and moved longitudinally within the framework of scales. The open framework itself can also be rotated as a unit. Thacher's Calculating Instrument was mounted on a mahogany base and produced by the Keuffel and Esser Company of New York.
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Date/Time | Thumbnail | Dimensions | User | Comment | |
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current | 22:52, 23 October 2014 | 3,635 × 1,813 (1.62 MB) | Gotanero (talk | contribs) | User created page with UploadWizard |
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Metadata
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Camera manufacturer | Canon |
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Camera model | Canon PowerShot ELPH 520 HS |
Exposure time | 1/60 sec (0.016666666666667) |
F-number | f/3.4 |
ISO speed rating | 160 |
Date and time of data generation | 10:39, 21 October 2014 |
Lens focal length | 4 mm |
Orientation | Normal |
File change date and time | 10:39, 21 October 2014 |
Y and C positioning | Co-sited |
Exif version | 2.3 |
Date and time of digitizing | 10:39, 21 October 2014 |
Meaning of each component |
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Image compression mode | 3 |
APEX shutter speed | 5.90625 |
APEX aperture | 3.53125 |
APEX exposure bias | 0 |
Maximum land aperture | 3.53125 APEX (f/3.4) |
Metering mode | Pattern |
Flash | Flash did not fire, auto mode |
DateTimeOriginal subseconds | 00 |
DateTimeDigitized subseconds | 00 |
Supported Flashpix version | 1 |
Color space | sRGB |
Focal plane X resolution | 19,000 |
Focal plane Y resolution | 19,000 |
Focal plane resolution unit | inches |
Sensing method | One-chip color area sensor |
File source | Digital still camera |
Custom image processing | Normal process |
Exposure mode | Auto exposure |
White balance | Auto white balance |
Digital zoom ratio | 1 |
Scene capture type | Standard |
Rating (out of 5) | 0 |