Posthuma Fosteri the description of a ruler, upon which is inscribed divers scales: and the uses thereof: invented and written by Mr. Samuel Foster, late professor of astronomie in Gresham-Colledg. By which the most usual propositions in astronomy, navigation, and dialling, are facily performed. Also, a further use of the said scales in deliniating of far declining dials; and of those that decline and recline, three severall wayes. With the deliniating of all horizontall dials, between 30 and 60 gr. of latitude, without drawing any lines but the houres themselves.

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Title
Posthuma Fosteri the description of a ruler, upon which is inscribed divers scales: and the uses thereof: invented and written by Mr. Samuel Foster, late professor of astronomie in Gresham-Colledg. By which the most usual propositions in astronomy, navigation, and dialling, are facily performed. Also, a further use of the said scales in deliniating of far declining dials; and of those that decline and recline, three severall wayes. With the deliniating of all horizontall dials, between 30 and 60 gr. of latitude, without drawing any lines but the houres themselves.
Author
Foster, Samuel, d. 1652.
Publication
London :: printed by Robert & William Leybourn, for Nicholas Bourn, at the South entrance into the Royall Exchange,
1654.
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Subject terms
Astronomy -- Early works to 1800.
Nautical astronomy -- Early works to 1800.
Navigation -- Instruments -- Early works to 1800.
Link to this Item
http://name.umdl.umich.edu/A40034.0001.001
Cite this Item
"Posthuma Fosteri the description of a ruler, upon which is inscribed divers scales: and the uses thereof: invented and written by Mr. Samuel Foster, late professor of astronomie in Gresham-Colledg. By which the most usual propositions in astronomy, navigation, and dialling, are facily performed. Also, a further use of the said scales in deliniating of far declining dials; and of those that decline and recline, three severall wayes. With the deliniating of all horizontall dials, between 30 and 60 gr. of latitude, without drawing any lines but the houres themselves." In the digital collection Early English Books Online. https://name.umdl.umich.edu/A40034.0001.001. University of Michigan Library Digital Collections. Accessed June 13, 2025.

Pages

CHAP. XVI.

Concerning re-in-cliners, that are di∣rect, or have no declination.

IF the line CB be placed (as is prescribed in the former figure) and drawn quite through, it will represent your plain that is re / in-clining towards the North, and without any declination. So also BL, if it be drawn quite through, will represent such plains as re / in-cline towards the South, and have no declination.

For which lines so drawn (or imagined only) you may gather (according to the former rules) which of the Poles (A or X) is elevated, and how much it is elevated (which is shewed by the arke CA or LX.) You may also see which end of the Meridi∣an is to be taken for the substilar line, over which (in these direct plains) the stile is ever to be erected, and must stand.

Then for drawing the houres, you have no more to doe, but to describe an Horizontall Diall to that

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elevation, which is due to the plain. The manner whereof is shewed before in the 11 Chap.

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