June 2023
Page 8

How to Use the Belgian Altitude Dial?

Reviews two methods suggested by Sue Manston for operating a portable altitude dial (a Hevelius dial). Geometric analysis confirms the two methods are equivalent, but practical tests suggest Method 1, using the shadow of a gnomon parallel to the short edge, is feasible for determining the time with 10–15 minutes accuracy.
Dials: Portable, How Sundials Work

Frans W. Maes

December 2018
Page 27

Readers’ Letters (1)

A reader questions the accuracy of the east-facing dial on Gouda town hall. By overlaying a correct pattern, the author concludes the hour lines are flawed and makes the tongue-in-cheek suggestion that the pattern might have been copied from local treacle waffles (stroopwafels).
Historical Dials, Sundial Design & Layout

Frans W. Maes

March 2011
Page 22

A Reconstruction of Ludwig Hohenfeld’s 1596 Polyhedral Sundial

This article describes the reconstruction of Ludwig Hohenfeld’s 1596 polyhedral sundial, a 26-sided rhombic cubo-octahedron, using distorted photographs and image editing software. It details the process of rectifying the faces and analyzing the sundials inscribed on them to estimate the design latitude.
Dials: Multi Faced, Sundial Design & Layout, Construction Projects, DIY Sundial Projects, Historical Dials

Frans W. Maes

December 2010
Page 7

Readers’ Letters

This section includes letters from readers. Frans Maes describes a multi-faceted obelisk sundial in Schwäbisch Gmünd, Germany, similar to one previously discussed. Allan Mills and Michael Lowne provide detailed explanations and practical advice on how to observe the optical phenomenon known as 'Haidinger’s brush,' which appears due to polarized light in the blue sky.
Dials: Multi Faced, How Sundials Work

Frans W. Maes
Allan A. Mills
Michael Lowne

December 2007
Page 173

Readers’ Letters

This section contains various letters from readers. Frans W. Maes discusses Lambert circles and seasonal markers on analemmatic sundials. Roger Bailey provides corrections and recommendations for seasonal markers. Frank King confirms a relationship for seasonal marker distance. Ken Head replies to Maes and Bailey. John Lester solves the mystery of a partial sundial motto. Malcolm Barnfield describes the making of a noon cannon sundial.
Dials: Analemmatic, Sundial Design & Layout, DIY Sundial Projects, The BSS and Members

Frans W. Maes
Roger Bailey
Frank King
Ken Head
J. P. Lester
Malcolm Barnfield