Introducing the 6th Edition of the Grimoire Quadrantis Telemetrum
BERLIN, 2026-01-27 -- WNDSN Applied Science Lab is pleased to announce the by now 6th and final edition of Grimoire Quadrantis Telemetrum (GQT6): WNDSN Quadrant Telemeters - Instruments for the Mastery of Time and Space. This new edition represents a decade of Telemeter development, research, and worldwide exploration. It is both a practical field manual and a technical reference, collecting the methods, worked examples, and reference data necessary to operate the Quadrant Telemeter and its specialized variants.
The comprehensive manual describes techniques for using the functions of the Telemeter, the universal Surveying Quadrant, the Astronomical Quadrant (formerly the Horary Quadrant), as well as the legendary Sine Quadrant.
Beginning with foundational concepts and progressing through advanced instructions, the book explains how the Quadrant Telemeter, an intentionally low-tech, naked-eye observational instrument, can be used to measure angular size, distance, height or depth, slope, altitude, and elevation via a range of sighting methods. The instrument combines an inclinometer and dedicated scales for sine, cosine, and tangent so that right-angled and oblique triangles can be solved graphically and analogically without digital tools. In addition to being a trigonometry-based graphical analog computer, the Quadrant Telemeter functions as a star compass and chart, a sundial, and a coordinate scale; GQT6 covers both the theory behind these capabilities and the practical workflows for field use of the Quadrant Telemeter as a self-contained working system.
The 6th edition clarifies naming conventions across the family of instruments and introduces substantive additions to the Astronomical Quadrant. The Astronomical Quadrant now includes a number of navigational stars and extended equal-hour lines that show the hours of twilight, expanding the instrument’s utility for celestial navigation and timekeeping. The text also tightens terminology by distinguishing the Surveying Quadrant as the generic instrument form used for terrestrial measurement and the Astronomical Quadrant as the specialized form oriented toward time and celestial observation. These naming updates are accompanied by new scales and symbols, fully explained within the manual, so users can immediately apply the revised conventions in the field.
GQT6 expands on the material introduced in the fourth and fifth editions and has grown to include 244 figures, 39 tables, 50 equations, 230 cross-references, 144 glossary entries, and 104 bibliography entries, now clocking in at 564 pages. The book presents graphically worked formulas and a wide set of reference tables to support hands-on calculation and measurement. Tutorials walk readers step-by-step through each function and method, making the manual suitable as both an introductory textbook for new users and a study guide for advanced practitioners. Community contributions from users in the field are incorporated throughout, and errata from prior editions have been processed and corrected to improve clarity and reliability.
The changelog represents a range of editorial and technical improvements made for this edition. Explanations have been simplified or expanded where needed, dozens of graphics were refined or redesigned, and additional required and acquired Telemeter skills are outlined so readers can track their learning progression. The layout was streamlined to keep the volume usable in the hand -- otherwise this edition would have exceeded 600 pages.
Intended use cases for the Quadrant Telemeter and its manual include field surveying without electronics, celestial navigation, practical instruction in trigonometry and analog computation, and expeditionary or tactical measurement where robust, low-tech instruments are preferred. GQT6 supplies the theoretical background, practical procedures, and worked examples to enable accurate measurements and conversions in environments where digital aids may be unavailable or undesirable.
Continuing the use of the now iconic cover design, paying homage to medieval mathematical and astronomical books; the styling of the title as a "Grimoire" is a play on textbooks of magic with instructions on how to make spells, talismans, and the like, "Grimoire Quadrantis Telemetrum" -- Textbook of the magic of Quadrants and Telemeters. Finally; the author's name at the top; "Filiusventi" is a hint at the practice of Renaissance scientists to latinize their names; venti is the wind, and filius the son.
The WNDSN Quadrant Telemeter is a low tech, naked-eye, observational instrument for measuring angles via various inputs and sighting methods. In addition, the Quadrant Telemeter is a graphical, analog computer providing functions to directly process or convert the acquired values. The Quadrant Telemeter allows the user to measure angular size and compute distance, height or depth of object, slope, altitude, or elevation; it provides an inclinometer as well as scales for the computation of sine, cosine, and tangent for a given angle.
Telemeters are WNDSN’s flagship products made in Germany. Available in brass for durability, acrylic for optical properties, and other materials for special applications, they feature exceptional design specifications and build quality, and are made to be passed on from generation to generation.
- Paperback, 564 pages
- Published: 2026-01-27
- Language: English
- ISBN-13: 979-8243846523
- Dimensions: 5.5 x 8.5 inches
A 320-page e-book edition is also available for purchase via the provided link.
GQT6 is available from January 27, 2026 at:
- https://www.amazon.com/dp/B0GJ51JZX8/
- https://store.wndsn.com/products/wndsn-quadrant-telemeters-official-manual-gqt6
Available editions, including the table of contents, a glossary, citation examples, as well as currently known errata:
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About WNDSN
Based in Berlin, WNDSN's Applied Science Lab develops and manufactures low-tech, high-utility tools and instruments with the objective of providing or enhancing "that, which can’t be improvised" in low-probability, high-impact scenarios where it is most needed, yet usually unavailable or non-permissive. The resulting products are measurement, calculation, and exploration instruments informed by the motto "Ex Mensura, Scientia" -- knowledge from measurement.
Mission
WNDSN [ˈwɪndsən] provides knowledge and tools for educating and training professionals and enthusiasts in the mastery of time and space.
WNDSN is devising instruments to measure values in the real world, calculate meaningful results from the acquired data, and process the insights as input for various problem solving tasks.
Products
WNDSN produces archival quality products that are designed with intent by combining techniques proven over centuries, bringing together the early history of science with cutting-edge, contemporary methods, resulting in iconic, timeless, high-utility designs in the spirit of the Renaissance.
WNDSN creates custom-built instruments and multi-purpose tools, metrology and illumination solutions with applications in urban reconnaissance, hostile theaters, disaster areas, and outdoor exploration.