Digital Version of Abridged Wndsn Quadrant Telemeters: Official Time & Space Manual (GQT4)

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Abridged version, 212 pages PDF, this same edition comes as a digital supplement included with every Telemeter bought.

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Description and use of the Telemeter, Horary, and Sine Quadrant. Abridged digital edition of the fourth edition.

The fundamental concepts of distance and altitude calculations, as well as advanced tutorials, formulas, and reference tables.

The Wndsn Quadrant Telemeter is a simple observational tool for measuring angles via various inputs combined with a number of means to directly process the acquired values. This instrument is equally useful in altimetry, surveying, etc., for taking altitudes, and determining right-angled triangles. This manual is about the theory and practice of the instrument.

The 4th edition reiterates the constituent concepts of calculating distance with reworked fundamental and clarifying graphics.

Efficient learning and accessible information is the overarching goal for the 4th edition. The examples and tutorials utilize only the most salient formulas and only require the Quadrant for measurements and computations (plus pen and paper for note-taking). The novice, the seasoned practitioner, and the educator looking to demonstrate mathematical concepts in tangible ways are equally addressed.

Using a Wndsn Quadrant Telemeter to determine latitude (at night with Polaris), calculate declination of the day with the respective arc, and a measurement of the Sun altitude (backsighting), one can derive at least 18 data points and actually calculate all of them directly on the quadrant.

  1. Digital (PDF) Edition Wndsn Quadrant Telemeters - Graphical Telemetry Computers: Official Manual

The manual provides background science and history, set up instructions, reference materials, and advanced tutorials on the following topics:

  • Quadrant and Inclinometer Operation
  • Measuring the Depth of a Well
  • Shadow Square Operation
  • Finding Tangent
  • Measuring from an Elevation
  • Measuring an Elevated Object
  • Finding Sine and Cosine
  • Using the Obliquity Arc
  • Extending the Scales
  • Powers of 10 and Scale Jumps
  • Measuring Angular Size
  • Measuring Size Instead of Distance
  • Resection: Triangulation, Trilateration, Triangulateration
  • Resection Error Margins
  • Small-Angle Calculations


  • Sun Sighting
  • Sun Calculations
  • Measuring Local Latitude
  • Measuring Sun Altitude
  • Using The Obliquity Arc
  • Traversing the Quadrant
  • Calculating Sun Declination
  • Calculating Sun Altitude

Horary Quadrant Tutorials:

  • Using the Calendar
  • Measuring Time
  • Seasonal (“Unequal”) Hours
  • Equinoctial (“Equal”) Hours
  • Solar Time


  • 212 pages, black and white
  • PDF
  • 8" x 5" (12.7 x 20.32 cm)

What's not included in the abridged edition?

  • Astronomy background
  • Sine Quadrant tutorials
  • Metrology
  • Device Calibration
  • Extensive reference tables