The British Sundial Society

Promoting the Art and Science of Gnomonics since 1989

On the 20th. January over 120 pupils at Cheney School in Oxford learnt about the principles of solar time-keeping and ancient Greek and Roman dials, saw a demonstration of how they work and built their own hemicyclium dial Рall within the space of an hour. The event, organised by the IRIS project as part of an ancient astronomy day, saw Chris Williams deliver a wide-ranging lecture on how the ancients told the time and the differences in their requirements for timekeeping and those we have today. An extract of the presentation, including various pictures of classical dials, can be seen here.

David Brown then took over, first demonstrating how shadows vary depending on the time of year and why a hemicyclium is more practical than a hemispherical bowl,

before each pupil was presented with a kit to make their own.

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The Ebenezer Chapel at Hebden Bridge was built in 1777.    The Particular Baptists outgrew it by 1857 and it became a Sunday School till 1883.  It was sold after the first World War and had various other uses until 1973 when, after being the offices of the Hebden Bridge Times, it became the village Arts Centre, and remains as such today.

The design latitude and declination are both inscribed on this fine dial, together with a motto which reads ‘Quod Petis Umbra Est’ (What thou seekest is a shadow). The sturdy gnomon has a decoratively sculpted lower edge, and although it is quite thin, there is an appropriate substyle gap in the chapter ring. Unusually for a vertical dial, it is flanked on each side by EoT corrections for 38 dates in the year.

As part of its educational activities the BSS is participating in an Ancient Astronomy day being run by the Iris Project in Oxford on 20th January.

Chris Williams will be presenting the theory and usage of Greek and Roman dials and David Brown will be leading practical exercises which will result in over 100 pupils from year 7 upwards making their own dials. More information in this Oxford Mail article, although the picture of an armillary sphere and reference to an orrery are both misleading – pupils will be making a hemicyclium dial (the small, cardboard version!):
Hemicyclium dial & models

We plan to record the day so photos, videos and even the model plans to follow.

UPDATE: Local interest is growing: the Oxford Times has devoted half its front page to the event but regrettably their write-up is also confused about dials and orreries.

A very happy new year to all our visitors.

Thanks to Fiona Vincent we are pleased to provide a table of Equation of Time adjustments and solar declination for 2015. It is provided in two formats, each of which can be printed on a single side of A4 and folded to make a two-sided A5 version. Depending on your preference, this one can be flipped along the long edge and this one along the short edge.

To print, download the relevant PDF (right click on the link and select “Save Link As…”). Open the file in Adobe Reader and select the following options in the print dialogue: “Actual Size” in the Size tab and 2 pages per sheet, Vertical page order and Landscape orientation in the Multiple tab .

Or you may prefer to wait for the printed version which will be included in the March Bulletin!

Thanks to John Lester for the following description:

Some would describe this dial on the church porch as Jno Berry’s masterpiece. It is certainly a fine dial though the slate has become badly cracked since it was engraved in 1762. It follows the usual pattern with winged heads in the top corners and the date displayed around the arch. Below this is a traditionally lugubrious motto, “Tempus fugit mors venit” (Time flies, Death comes) and underneath that a sun face surrounds the gnomon root. A further motto appears below which reads “Nos ut umbra” (We are like a shadow). The hours shown are VI to VI with a decorative cipher at noon. The half hour divisions each have a fleur-de-lys decoration and quarters are also shown.¬† The dial not only has 12 declination lines which show the length of daylight in Arabic numerals and, less precisely, the signs of the zodiac, but also set of vertical lines indicating the direction from which the sun is shining. As if that were not sufficient, Berry has provided lines which tell us the time of noon, relative to our own local time, at eleven places around the world! Of the more obscure ones, Fort St. George and Surat are on the East and West sides of India while Port Royal was the original name of Kingston, Jamaica. Finally, the maker has added his own name at the bottom of the plate in modestly small letters. Even Pevsner mentions this dial though he offers no praise whereas Mrs Gatty devotes generous space to it and gives details of Berry’s life.

Maud Heath was a pedlar woman who in 1474 left sufficient money to endow the causeway which crosses the Avon just before it reaches Chippenham in Wiltshire.¬† The best preserved section is a raised footpath supported by 64 brick arches, allowing the river to flow underneath in times of flood.¬† Half way along the causeway, at Kellaways, stands a pillar erected in 1698, and bearing this cube sundial.¬† The original Latin mottoes were translated by the Rev W L Bowles and inscribed on the lower section c 1828.¬† The Rev Bowles had a reputation for absent-mindedness.¬† At a school prize-giving he presented a Bible to one child, having written in it “With the author’s compliments”.

Two other dials grace the causeway.¬† Towards the eastern end, at East Tytherton, a very vandal-proof quincentenary memorial dial was built in heavy stone in 1974 (SRN 3089), and at Langley Burrell, at the western end, you will find a well preserved small vertical of 1719 on the church of St Peter’s (SRN 3085).