Looking for the Wndsn store? This way, please.

Introducing the WNDSN Sine Quadrant

BERLIN, 2020-11-11 - A thousand years after its invention, WNDSN makes available the mighty Sine Quadrant again.

When I consider what people generally want in calculating, I found that it is always a number. --Muhammad ibn Musa al-Khwarizmi (c. 780-850)

The Sine Quadrant or sinecal quadrant in the English speaking world, was first developed in 9th century Baghdad and remains unmatched in determining celestial angles, telling time and the calendar, finding directions, and determining the apparent positions of any celestial object for any time.

The Sine Quadrant is an instrument for the true enthusiast, a mathematical tool to solve trigonometric calculations. Spurred on by the popularity of the WNDSN Sine Quadrant Worksheet Pad, this large format Sine Quadrant is 6.25”/16 cm long and is made with High-Viz laser-engraved, ~1/8" (3.2 mm) matte white Acrylic stock with a black core. While the paper Sine Quadrant is designed for use with pen and compass, the acrylic Quadrant features a string that can be attached to its vertex and is used to perform calculations by positioning it across the scales, much like the other flagship Telemeters in the WNDSN line of instruments.

The Sine Quadrant is unassuming at first glance, of what merely amounts to graph paper. Unlike the Horary Quadrant which gives away some of its functions on sight or at least hints at its capabilities, the Sine Quadrant is rather opaque, with nary a hint at its powerful functionality. Yet, it is the most elegant of tools. If you don’t know what they are, the scales appear to be no more than decorative patterns. However, the interaction between the sexagesimal scales on the straight edges and the 90 degree angular scale on the arc, allow a range of graphic calculations, from the simple finding of a sine, to the complex, dividing a sine by a cosine in order to determine the bearing of the Sun.

The WNDSN Sine Quadrant has a number of functions:

  • Measure degrees from vertical or horizontal
  • Determine true vertical.
  • Calculate sine and cosine.
  • Read declination for a given day.
  • Perform graphical computations between angles, trigonometric ratios, and sexagesimal values, along with determining great circle calculations, diurnal arcs, hour angles, azimuths, latitude, and determining cardinal directions.

More than a thousand years after its invention, WNDSN is now making the Sine Quadrant commercially available again. WNDSN’s goal is to use the Sine Quadrant to teach the concepts of graphical calculations to modern audiences and to encourage the pursuit of arcane mathematics in everyday life.

The WNDSN Sine Quadrant is accompanied by a special 150-page, digital edition of the Grimoire Quadrantis Telemetrum that supplies the relevant astronomical instruction and tutorials in graphical trigonometry.

Available at:



WNDSN's Applied Science Lab, based in Berlin, develops and manufactures that which can't be improvised; measurement, navigation, and surveying instruments informed by the motto "Ex Mensura, Scientia" -- knowledge from measurement.

WNDSN produces archival quality products that are designed with intent by combining techniques proven over centuries; arcane science meets cutting edge contemporary methods, resulting in iconic, timeless, high-utility designs.

In addition to custom-built instruments and tools, metrology & illumination solutions, WNDSN creates expedition mementos and morale patches to celebrate cross-disciplinary exploration in the spirit of the Renaissance. WNDSN morale patches are acutely designed -- no line is left to randomness, no element is mere filler. They serve as infographics, how-tos for the WNDSN tools, magic sigils, as well as functional markers.