This sundial is something rather special. This decorative dial is both elegant and very complex. It must have taken a long time to devise and lay out accurately. It stands in the extensive grounds of the elegant Abbey Church of St Georges de Boscherville in Normandy. I managed to get hold of a small pamphlet in the Abbey bookshop – it wasn’t on display, and I had to go back to collect it once they found one. Even then I failed to understand the sundial properly, and not simply because of my rusty but workable French. I’m not even going to attempt to describe it, but it photographs well in its picturesque setting, and I have included a shot of the explanatory plaque at the end for the science-minded.
One fact I learnt is that until WWII, France was on Greenwich Meantime. During the occupation, the Germans changed the time zone to Central European time, a practice that has remained ever since.
Does this help?
ROLLING HARBOUR GALLERY 
The most interesting is why they constructed such a complicated sundial at a time when clocks and watches were available. Amelia
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Because… They had helio-apps on their phones to work out the angles, rotational axes, sun declinations, plotter radii and star signs simultaneously!
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The globe tips are parallel to the axis of rotation of earth and thus point to the poles, and north star. It can be read by looking at the shadow of the metal point or the edges of lighting. The sun goes around it like it does the earth or they both spin together. The location of the sun’s zenith point on the earth is the same on the sphere. The Lines are of time and longitude.
https://www.google.com/search?q=globe+sundial&biw=988&bih=716&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiH7d3ft7bSAhVMz1QKHSY8AxAQ_AUIBygC#tbm=isch&q=sphere+sundial&*
The other one is you need to know which horizontal line belongs to today’s date. You can interpolate it between lines. Then where the shadow crosses the line on today’s date, is the time. It can be googled using “shepherd’s-sundial”. This one uses a disk instead of a movable arm to cast the shadow.
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Thanks so much for this and your other v helpful explanation. Sorry for the delay in replying – I waited until I had time to look at it more closely. It’s clearer now. I post quite a few sundials… and I’ve realised just how incredibly complex (to the layman) they can be – including early ones. I recently photographed some in Florence. I’ve posted a simple one from the Ponte Vecchio; when I have time I’ll be tackling Santa Maria Novella… Thanks for calling in. RH
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This one the signs of the zodiac are the dates and the numbers the hour.
The idea is there are three dials in the photos and the shadow is the same for all. It can be instructive on how they work if they are seen all at once. More points of view.
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Many thanks for this and your other explanation. RH
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