September 2012 page 20
Mike Cowham

The Planispheric Nocturnal

This article describes the planispheric nocturnal, an instrument for telling time at night by aligning a rotating star chart with actual stars. It functions as an alternative to a traditional nocturnal and can be found on the reverse of some quadrants, offering timekeeping to within 15 minutes without requiring Equation of Time correction.
Dialling Tools, How Sundials Work, Dials: Nocturnals

December 2012 page 11
Michael Lowne
Steven Woodbury

Readers’ Letters

This section features two letters: Michael Lowne corrects a misconception regarding the alignment of the Plough's pointer stars with the pole star for planispheric nocturnals, impacting time readings. Steven Woodbury provides observations and a solution for the Dutch Polyhedral Dial drawing, noting its equatorial and polar dials and non-latitude specificity.
Dials: Multi Faced, Dials: Nocturnals

March 2010 page 28
Mike Cowham

Dial Dealings 2009

A review of sundials sold at auction in 2009. Notable items include a gilt brass compendium by Charles Whitwell dated 1608, a Panorganon by Joseph Wells, a Gunter's quadrant by Henry Wynne, and a silver Butterfield dial by Pierre le Maire.
Dials: Portable, Dials: Scaphe, Historical Dials, Dials: Nocturnals

September 2010 page 10
Michael Lowne
John Davis

The Horizontal Quadrant. Pt. 2: Use, and the Inverted Quadrant

This article details the use of horizontal quadrants for time-finding and surveying, including a rare 'inverted' variant. It describes how to determine time from solar altitude and declination, and from stars at night, discussing the historical accuracy and limitations of these instruments.
How Sundials Work, Mathematics of Dialling, Historical Dials, Dials: Nocturnals

December 2009 page 14
Valery Dmitriev
Malcolm Barnfield

New dials

This section presents two new dials. The first is a stone vertical dial near St Petersburg with a theme from a Chekhov story. The second is a 'triple horizontal dial' made of stainless steel for a garden in South Africa, which includes a nocturnal and family anniversary lines.
Dials: Horizontal, Dials: Unusual, Dials: Nocturnals

December 2007 page 189
Mike Cowham

Book Review

This is a review of 'Catalogue of Sun-dials, Nocturnals and Related Instruments in the Instituto e Museo di Storia Della Scienza, Firenze' by Anthony J Turner. The catalogue details Florence's collection of sundials, nocturnals, and other instruments, categorized using Higgins' classification. The reviewer praises the initiative but criticizes the illustration presentation, including identification, placement, size, and photographic angles.
Book Reviews, Dials: Multi Faced, Historical Dials, Dials: Nocturnals

February 2006 page 6
Karl G. Hofbauer

‘The Moon Has Set And The Pleiades’ - Sappho; Time Measurement in Cultural History

Drawing on Sappho's poem, this article explores the history of time measurement, from ancient astronomical principles to modern atomic clocks. It examines the evolution of the term 'hour,' different timekeeping systems (Babylonic, Italic, canonical, equal), and how celestial phenomena like moon phases and the Pleiades were interpreted to determine time and seasons.
How Sundials Work, Historical Dials, Dials: Nocturnals

February 2006 page 14
Norman Darwood

A Moon Dial

This article provides instructions for assembling and using a moon dial. It explains how to determine the moon's phase using the Golden Number and how to rotate the dial to find the current time. The author notes that this dial relies on estimating the moon’s direction rather than casting a visible shadow, due to the moon's light intensity.
Dials: Equatorial, Dials: Unusual, Construction Projects, DIY Sundial Projects, Dials: Nocturnals

March 2005 page 3
Michael Lowne

Moondials and the Moon

Explores principles and types of moondials, including tabular, volvelle, graphical and adjustable designs. Analyses moon’s orbital motion, parallax, illumination, and visual limitations under moonlight. Proposes improvements to enhance accuracy towards that of simple sundials, and presents prototype experimental dials demonstrating refined timekeeping performance.
Dials: Nocturnals

June 2005 page 63
Patrick Powers

Reader’s Letter

Letter recommending WinEphem software for calculating moon transit times useful for moondials. Notes features such as rise/set/transit data and accuracy for dialling purposes.
Dialling Tools, Dials: Nocturnals

September 2005 page 106
Fiona Vincent

Major Lunar Standstill

The author describes the term 'lunar standstill' coined by Alexander Thom, as analogous to a solstice. The article explains how the moon's declination affects its rising and setting points and how this affects the reading of 'moon time' from a sundial.
Dials: Nocturnals

June 2002 page 76
Mike Cowham

Telling the Time at Night

Explores historical and modern approaches to determining time after sunset using nocturnals and other devices.
Dials: Vertical, Dials: Portable, Dials: Astrolabe, Historical Dials, Dials: Nocturnals

December 2002 page 135
Tony Belk

The Isaac Morris Moondial

A detailed explanation of a unique 1803 sundial with a moon time calculator by Isaac Morris, exploring its design, mathematics, and possible use for tide prediction.
Historical Dials, Dials: Nocturnals

June 2001 page 73
Sven Olof Larsson

A Stardial

The article presents the Stardial, an innovative device functioning as an equatorial sundial by day and a simplified astrolabe by night. Designed for simplicity, accuracy, and originality, it enables automatic conversion from local solar time to clock time and provides methods for precise time-telling using bright stars and even the moon.
Dials: Equatorial, Dials: Unusual, Dials: Astrolabe, DIY Sundial Projects, Dials: Nocturnals

June 1993 page 2
Giovanni Paltrinieri

Il Quarantale, An Unknown Instrument by Geminiano Montanari

This article details the discovery and analysis of the 'Quarantale', a lost gnomonic instrument invented by Geminiano Montanari, found through manuscript inscriptions related to a meridian line in Bologna. It explains how the instrument was designed for stellar observations, covering a 140° meridian arc to cover two apertures, by using a unique optical sight and mathematical calculations based on similar triangles, restoring its historical context.
Dials: Noon Lines, Dials: Unusual, Historical Dials, Dials: Nocturnals

February 1992 page 11
Rear-Admiral (Rtd) Girolamo Fantoni (Italy)

Moondials

This article reviews historical techniques for telling time by the moon, noting their limited accuracy due to the moon's irregular movements and the need to convert lunar time to solar time. It describes methods like using correction tables (e.g., Queen's College, Cambridge, or Rene Rohr's diagram) and specific moondial instruments (Oronce Fine, Bion). The author also proposes a new model of lunar dial, adapting a horizontal sundial with "lunar hour lines" as spiral curves.
Dials: Unusual, Dials: Nocturnals, Sundial Design & Layout

June 1992 page 3
Christopher Daniel

The Sundial at Sea

This lecture explores the practical aspects of 16th and 17th-century navigation, highlighting the crucial role of sundials and similar instruments for determining time at sea. Mariners used celestial observations for latitude, magnetic compasses for direction, and various tools like traverse boards, sand-glasses, nocturnals, astrolabes, and cross-staves for navigation and timekeeping.
Dialling Tools, Dials: Portable, Historical Dials, Dials: Nocturnals

June 1992 page 38
Denis Schneider

A Tidal Dial

This article explores the concept of a tidal dial for estimating tidal times, acknowledging the moon's primary influence on tides over the sun. It discusses the 'Port Establishment' and 'Lunar Situation,' and how a specially designed watch or optical sight, combined with knowledge of the moon's age, could provide approximate tidal information globally, even correcting for hydrographic board errors.
Dials: Unusual, Dials: Nocturnals

October 1991 page 16
René R.-J. Rohr

The Da'ire-Yi Mu'Addil

Rene R.-J. Rohr introduces the 18th-century Islamic instrument known as the "da'ire-yi mu'addil" (equatorial circle), used for determining daily and nightly prayer times. Driven by religious prescriptions, Islamic scientists developed sophisticated astronomical and mathematical methods. This instrument, although not mathematically precise, allows for the determination of prayer times, especially night prayers like isha and subh, through observation of the sun and moon's positions.
Dials: Equatorial, Historical Dials, Dials: Nocturnals