Sometime back I read in French of a Roman villa remains (Domitian) in Provence- with - I think I got this right, a wall mounted 'horologi' but without any detail it went on to say that it was a very rare example. I have researched widely but found nothing that illustrates this annoying description.I assume it was a sort of sundial? Can anyone tell me or direct me to a site?

That's a type of sundial known as a "vertical sundial" - the Roman writer Vitruvius does describe them sketchily, so they were known at the time you refer to.
Here's a link to one at the Tower of London.
http://images.search.conduit.com/ImagePreview/?q=vertical%20sundial&ctid=CT2645238&searchsource=1&start=35&pos=26

This gives an account of horologia P.
http://www.ancientsites.com/aw/Article/1120774
Also this, I had to include it because of the wonderful concept of 'posterior cultures'.
http://www.eaae-astronomy.org/sundials-project/index.php?option=com_content&view=article&id=48&Itemid=63

Thank you both. I have saved those sites also. The one I mentioned was unlikely to be wall mounted, it seems - possibly a wind tower of sorts - or a bowl. I ought to set Paul onto it via the French site.

What does 'posterior culture' mean? In that context, at least. care should be taken when defining others.

My thanks, P.

Good question… one that’s always intrigued me… (is that groans of ‘it doesn’t take much I hear’).


I asked a not too dissimilar question on the Beeb some time ago… ref roman numerals and counting etc.
Sundials are fine, so long as you stay in sight of it unless a compass was also used, and I’m not sure such a device was available in the times P is referring to. Certainly they crop up on the antiques road show from time to time.
So how was the passage of time measured for the ‘man on the move’… the sunrise… and the sunset is a good start, but what marked the time between those two points? Had hours and minutes been ‘invented’… they were pertinent to mathematics from a very early time, but was that for the passing of time or just a word to name the degrees of arc… it could just have easily been carrots or apple tarts.
And would the roman soldier have understood when to ‘synchronise’ the phases of the moon etc to launch a combined attack on an enemies position…? Was it expressed as X thingies past II in the morning… if you get my drift. Or 10 past 2… there must have been something to measure the passing of time on the move in those far away days.


Egg timers… who invented them. Bit hard to travel with a water clock as well. It’s hard to track the passage of the sun across the heavens when there’s nothing static to reference it to…


I used to make wooden clocks as a hobby, and drag them all over the place to craft fairs etc… but I remember sat in the tithe barn at Glastonbury years ago, a beautiful huge wooden structure with clay tiles that kept the rain out… but from my stall and looking up to admire the height and timbers of the roof, I was able to see countless tiny holes where the sunlight streamed in casting a myriad of tiny light spots on the cobbled floor. But that was the first time I’d actually seen the earth was spinning… and it was quite fascinating to watch the sunspot creep across the floor, quite visibly moving.


Sorry P to barge in on your thread.

Roman hours were rather plastic, not accumulations of minutes but set divisions between between sunrise and sunset. As the seasons changed they tended to expand to contract. A sundial's function therefore was not so much to measure time as a linear constant but to indicate time elapsed and time remaining between activities which coincided with the divisions of the day.

The egg timer principle is extremely ancient. Water and sand clocks, which are basically just containers with holes in them, have been excavated from periods as far back as 15,000BCE. And yes, their primary function might well have been in preparing food, especially baking and cooking.

Mmm, but does not further trying to fathom the very rare timing thingy found in the Roman villa remains - circa Ahenobarbus Domiti, I assume, but there were other Domitii who moved about there. This villa is in the hills north of Aix and not near Narbo where the Domitii had more dominance.

Time and its noted passage is an absorbing and complex study - and fraught with problems when trying to write on it. Throw latitude into the ring and the head reels. I still wonder how I ever once had the audacity.

Regards P.

I have just realised that HRH stands for His Res Historica - just a passing thought.

Just been considering the name. Could be that it was derived from the Tower of Winds horologion in Athens.

Without a more exact description of it and why it's considered rare it's difficult to know.

The Romans over centuries absorbed a lot of technology and techniques, and with all the variations regarding their attitude to time measurement thrown in to the mix it really could have been anything.

Priscilla, can you remember where you read it? It doesn't help that the modern French word for public clocks matches so closely the old romantic word. It makes searching texts difficult.

Thank you for the interest, no I do not have the source to hand - not in this country, anyway. If I track it down, I shall reopen the thread. The Tower of winds is interesting. It was mentioned on the second site that ferv gave. What an octagonal tower has to do with time I could pursue. The villa is close to strong tribal areas of the time - so, I then wonder how did the Gauls pre Roman mark the passage of time?
I know of their new day beginning at sunset but nothing of how their day was otherwise remarked.

Regards, P.

In Greece the eight wind deities represented passage of time on a yearly scale. Each wind they represent is one with a specific character which blows at a particular time of each year. It is believed therefore that a building dedicated to these deities was a logical place to construct public timepieces and the Horologion of Adronikos was known to contain at least three devices at the same time (sic), the combination of which for purposes of cross-reference probably made it the most exact clocktower in the world in its day.

In Crete I was a guest of an archaeologist in Lassithi one time and he explained to me why the vast majority of the windmills endemic to the region were not, like their northern European equivalents, designed to swivel and thereby utilise all wind directions. In the opening to the plain the wind was funnelled through the gap almost all year round, which explained why the ones near that area all faced the gap. However the others (and at one stage there were up to 1500 or more in the area) were dedicated to particular tasks. Those involved in grape or olive pressing, for example, needed only to face the autumn wind (nor' nor'west). Those drawing water faced the spring wind (so'west) and feathered their sails in autumn when the weaker prevailing wind kicked in from the almost exact opposite direction- Those grinding grain were in fact swivelled, but there were not so many of them. So predictable are these winds in the area that until mechanisation in relatively recent times neither the location nor the design of these windmills needed to be changed much at all over millennia.

Re the Gauls - if they were similar in customs and technology to the Irish Gaels of the period then they used sun-dials, water clocks and tallow clocks. Much like the Romans, then.

nordmann wrote:

Re the Gauls - if they were similar in customs and technology to the Irish Gaels of the period...

Of course they were similar, if not identical - Celtic fraternity and all that...

(scurries away and hides, just like all those generations of Druids [who built Stonehenge] did from the Claudian invasion until their re-emergence 17th century...)

Not sure any such thing existed (until it was invented in the 19th century)

Indeed, but there's an awful lot of money to be made from telling 'Celt'-enthusiasts whatever they want to hear...

You've noticed?

Indeed I have, and if I knew what was good for me I'd probably have had a go at milking that cash-cow myself (look out for: ed. Catigern, 'Pan-Celtic Vegan Feminist Democracy, from Ancient Gaul to Modern Massachusetts - an Illustrated Spiritual Journey', Cambridge University Press, 2013 ).

Here is a picture of Peter Beresford Ellis bouncing all the way to the bank...

There is, of course, this example of the first wrist watch

http://www.astro.rug.nl/~weygaert/antikytheramechanism.html

https://www.youtube.com/watch?v=xo74Dn7W_pA

Take a look at 1:03

nordmann wrote:

Roman hours were rather plastic, not accumulations of minutes but set divisions between between sunrise and sunset. As the seasons changed they tended to expand to contract. A sundial's function therefore was not so much to measure time as a linear constant but to indicate time elapsed and time remaining between activities which coincided with the divisions of the day.

The egg timer principle is extremely ancient. Water and sand clocks, which are basically just containers with holes in them, have been excavated from periods as far back as 15,000BCE. And yes, their primary function might well have been in preparing food, especially baking and cooking.

I've never understood why the Romans didn't go in for decimal time measurements rather than duodecimal (i.e. dozenal) time measurements. Decimal time units were certainly used in ancient China and also in Revolutionary France in the 1790s. Also - and as an aside - it seems that the terms 'decimal time' and 'metric time' have swapped names. Surely 'decimal time' (i.e. 10 hours, 100 minutes, 100 seconds) is really metric time and 'metric time' (i.e. decimal fractions of seconds) is really decimal time.

The Romans inherited a 24 hour day via Greek influence very early in its establishment as a city state ultimately from ancient Babylonian origins (could be older - we just can't trace it back further). However when it came to measuring these hours the Romans realised quite early on that the Greek divisions just didn't work that well and that imported sun-dials showed only two periods in the year when the etching matched the shadow, so to speak. Amazingly they put up with this for quite a while - several centuries in fact - and it seems to have been only during the period of the Punic Wars that they were spurred into addressing the issue, though the timing (pardon the pun) of both developments might have been a coincidence. This was when they made the radical departure from their Greek inheritance and invented midnight, a crucial element in caculating the "horae", which although divided into two twelve hour cycles had always been of variable length. Once calculation could be accurately measured then the day's hours could be based not only on their own latitude but also be of fixed length. A censor called Q. Marcius Phillippus marked the occasion with the gift of an official horologium, the Roman equivalent of our atomic clock servers that can be used to keep data systems etc in synchronisation.

This, I imagine, was the moment when the Romans could indeed have switched from duodecimal to decimal had they wished to. Basically the entire system was open to review. However I imagine that it was extraneous social issues revolving around timing according to the inherited system that convinced them to stick with it. After all, the number of hours in the day was less important than making sure they were consistent and predictable.

Also it is worth remembering that the Romans had two ways of defining a day. The civil day, that which the horologium was designed to measure, was the one integrated into the wider calendar. Being predictable it obviously had big implications both militarily and administratively in an ever increasing empire in terms of size. However the natural day, also divided into two twelve hour periods but of traditionally variable length, was still the one the vast majority of people lived by. Having a duodecimal and decimal system coexisting would have been probably regarded as just too much for the average person to take on board.

A bit like Britain and Ireland in the run-up to the introduction of decimal coinage. Anyone remember "Granny Gets The Point"?

My word - it's on You Tube. What's not these days?

I have to say that Granny is the only cast member whom I identify with. I can't help feeling that it's not the maths that she finds upsetting (she's quite likely the best in the family at mental arithmetic) - no - it's more to do with the first line of George Orwell's Nineteen Eighty-Four:

'It was a bright cold day in April, and the clocks were striking thirteen.'

I suppose another reason why decimal time has never caught on is that there would rapidly be the need for a unit smaller than a second. A decimal second would be 14.4 dozenal (or sexagesimal) seconds long. That is simply too long for any practical purpose. While a hundredth of a decimal second would be too quick. A tenth of a decimal second at 1.44 dozenal seconds might work though. That said - if a standard human heartbeat is roughly 72 per minute then a dozenal second would still be closer to it than a decimal second.