December 2009 page 34
Rafael Soler

A double catenary bifilar sundial for the Balearic Islands University Campus

This article describes a large and innovative bifilar sundial. It uses the intersecting shadows cast by two suspended chains hanging in catenary curves to indicate both the time and the date on a large tiled pavement. The article provides a summary of the complex mathematical calculations involved in its design.
Dials: Bifilar, Dials: Unusual, Mathematics of Dialling, Sundial Design & Layout

June 2008 page 77
Chris Lusby Taylor

The 2008 BSS Conference, Latimer

This report summarises the 2008 BSS Annual Conference at Latimer, highlighting various talks including Piers Nicholson on Jantar Mantar, Chris Williams on scratch dial statistics, Fred Sawyer on Michnik's bifilar sundial, Celia James on James Richard's dial, Julian Lush on Armenian scallop dials, and John Davis on John Rowley's work.
Dials: Bifilar, Historical Dials, Sundial Design & Layout, The BSS and Members

December 2007 page 184
Rafael Soler Gayá

A Multiple Dial as a Monument to the Fishermen of Cala Figuera, Santanyi (Majorca)

This article describes a monument in Cala Figuera, Majorca, featuring three vertical declining bifilar sundials on the pedestal of a fisherman statue. Two dials face south, one east and one west, and the third faces north, declining east. The article details their bifilar gnomon design (semi-ellipse and straight line), delineation for hours and half-hours, and declination lines, along with the mathematical methods used for their design and calculation.
Construction Projects, Dials: Bifilar, Dials: Multi Faced, Mathematics of Dialling, Sundial Design & Layout

September 2002 page 115
Margaret Stanier

The Twentieth Century

An essay reflecting on the evolution of sundial making and the Society's activities during the 20th century, highlighting significant developments and personalities.
Dials: Bifilar, Dials: Equatorial, Dials: Heliochronometer, Dials: Unusual, Historical Dials, The BSS and Members

February 1995 page 18
Fred Sawyer

Bifilar Gnomonics

An explanation of the bifilar sundial's geometry and time-telling principles, including its unique two-thread gnomon and analytical methods for calculating its layout.
Dials: Bifilar, Mathematics of Dialling

February 1993 page 36
Fred Sawyer

Bifilar Gnomonics

This paper elaborates on the theory and construction of bifilar sundials, a twentieth-century type invented by Hugo Michnik. It highlights their equiangular hour-lines, allowing direct reading of standard clock time by simple daily adjustment, and explains how time is indicated by the intersection of shadows from two horizontal threads.
Dials: Bifilar, Dials: Unusual, How Sundials Work, Mathematics of Dialling, Sundial Design & Layout

October 1993 page 40
Fer J. de Vries

Bifilar Gnomonics

This article presents a general method to transform a 'normal' sundial layout into a bifilar sundial, suitable for all flat dials, not limited to equiangular hour lines. It explains how to calculate thread heights for the resulting sundial drawing.
Dials: Bifilar, Mathematics of Dialling, Sundial Design & Layout

February 1992 page 36

Letters to the Editor

This section contains several letters. H.R. Mills provides mathematical formulae for an analemmatic dial, J.G. Freeman describes the bifilar sundial with two horizontal wires, and Alex Monroe encloses a photograph of his portable equatorial dial. M.J. Cowham contributes notes on John Worgan's work, highlighting a distinctive English Rose design on his instruments.
Dials: Analemmatic, Dials: Bifilar, Dials: Equatorial, Dials: Portable