The triangular quadrant, or, The quadrant on a sector being a general instrument for land or sea observations : performing all the uses of the ordinary sea instruments, as Davis quadrant, forestaff, crosstaff, bow, with more ease, profitableness, and conveniency, and as much exactness as any or all of them : moreover, it may be made a particular and a general quadrant for all latitudes, and have the sector lines also : to which is added a rectifying table to find the suns true declination to a minute or two, any day or hour of the 4 years : whereby to find the latitude of a place by meridian, or any two other altitudes of the sun or stars / first thus contrived and made by John Brown ...

Title

The triangular quadrant, or, The quadrant on a sector being a general instrument for land or sea observations : performing all the uses of the ordinary sea instruments, as Davis quadrant, forestaff, crosstaff, bow, with more ease, profitableness, and conveniency, and as much exactness as any or all of them : moreover, it may be made a particular and a general quadrant for all latitudes, and have the sector lines also : to which is added a rectifying table to find the suns true declination to a minute or two, any day or hour of the 4 years : whereby to find the latitude of a place by meridian, or any two other altitudes of the sun or stars / first thus contrived and made by John Brown ...

Author

Brown, John, philomath.

Publication

[London] :: To be sold at [his, i.e. Brown's] house, or at Hen. Sutton's ...,

1662.

Rights/Permissions

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Subject terms

Quadrant.

Dialing.

Mathematical instruments.

Link to this Item

https://name.umdl.umich.edu/A29764.0001.001 content_copy

Cite this Item

"The triangular quadrant, or, The quadrant on a sector being a general instrument for land or sea observations : performing all the uses of the ordinary sea instruments, as Davis quadrant, forestaff, crosstaff, bow, with more ease, profitableness, and conveniency, and as much exactness as any or all of them : moreover, it may be made a particular and a general quadrant for all latitudes, and have the sector lines also : to which is added a rectifying table to find the suns true declination to a minute or two, any day or hour of the 4 years : whereby to find the latitude of a place by meridian, or any two other altitudes of the sun or stars / first thus contrived and made by John Brown ..." In the digital collection Early English Books Online. https://name.umdl.umich.edu/A29764.0001.001. University of Michigan Library Digital Collections. Accessed May 21, 2024. content_copy

Contents

• title page
• half title
• treatise on triangular quadrant
  • The Description.
    • An Advertisement.
  • THE USES:
    • I. To find the suns declination, true place, right assention, and rising, the day of the moneth being given.
    • II. To find the Suns or a Stars Altitude, by a forward Observation.
    • III. To perform the same another way.
    • IIII. To find the suns Altitude by a back ob∣servation,
    • use of triangular quadrant - 5
    • VI. To find the suns distance from the zenith, by observing the other way, the sun being not above 60 degrees high, or 30 from the zenith.
    • use of triangular quadrant - 7
    • VIII. To find an observation by thred and plummet, without having any respect to the horizon, being of good stead in a misty or cloudy day at land or sea.
    • use of triangular quadrant - 9
    • X. To find a latitude at Sea by forward me∣ridian Observation or Altitude.
    • XI. To find the latitude by a backward Me∣ridian Observation at Sea.
    • XII. To find a latitude with thred and plum∣met, or by an observation made without respecting the Horizon.
    • The Declination of the Sun being given, or rather the Suns Distance from the Pole, and the Complement of two Altitudes of the Sun, taken at any time of the day, knowing the time between: to find the Latitude.