Greek - Roman Water Power #1

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Greek - Roman Water Power #1

Postby Marcus Minucius Audens » Sat Sep 24, 2016 9:01 pm

>>>> Greek - Roman Water Power #1 <<<<

In researching the true beginning of the use of water power in order to turn machinery, the literary volume of material is unusually silent. Aside from a mention of the power of moving water in an early Greek poem, there is little information until we reach the area of the first century BC. In that period it is the geographer Strabo (XII, 3, 40) who mentions the construction of a ‘water mill’ somewhere in the kingdom of Mithridates at Kabeira in the Pontus (near the modern Niksar, N. central Turkey). This period is sometime before the earliest in either Italy or Greece. Since the simple requirement for a water wheel establishment is the constant supply of water throughout the whole year, and the quantity of water in that supply must be quite large, if the activity is to produce enough power to be useful, the explanation may be simply that such a use was obvious. The city of Mithridates stood close by a river, the Lycus [modern Klkit) which contained a substantial flow and which has a rather large area from which to gather a sufficient rainfall harvest. However, once such an establishment is put into place, then the builders will need to deal with other significant problems dealing with both the management, as well as, the conservation of water supplies in periods of fluctuating inventories such as in droughts or floods.

Essentially, there are three mentions in literary sources that indicate the knowledge of a working water wheel. The first is Vitruvius (late first century BC) and, of course, is the most important as his is a very clear and full description of an undershot water-wheel which we shall discuss at a later time. The second is a mention in a Greek epigram from the Palatine Anthology (IX, 418) which speaks of the water-mill, constructed on some sort of country estate, which has removed the necessity of the local women to grind grain by hand. The author of this piece is probably Antipater of Thessalonika, who was closely associated with the Pisones, a Roman noble family. His work dates from the end of the first century BC and equates with the Vitruvius discussion with one exception. Antipater’s poem mentions, “Nymphs [which personify the water] as leaping down onto the topmost part of the wheel.” From this we get the very positive idea of an overshot wheel which can be classified as a much more efficient style of machine than the one described by Vitruvius and it also considers the matter of a priority in such discoveries.
The third meaningful item, is an allusion in a Poem,”On the Nature of the Universe,” by Lucretius (V, 509-33, particularly 515-6) in which he mentions a current of air circulating around the universe, causeing the “sphere to rotate, as we see rivers turning wheels and buckets (rotas atque haustra).” In this mention, the author was clearly referring to the use of water-wheels as an item familiar to his readers. However, in this poem Lucretius was writing some 40 years before the other two. This item suggests that the discovery of the use of pumps [bucket wheels or bucket chains] were known earlier than the use of water-wheels for the task of milling grain.

Reference:
>> J.G. Landis, “Engineering In the Ancient World,” (Univ. of Calif. Press, Berkley, 1981).

Respectfully Submitted;
Marcus Audens
Marcus Minucius Audens
 

Re: Greek - Roman Water Power #2

Postby Marcus Minucius Audens » Mon Sep 26, 2016 12:03 am

>>>> Greek -- Roman Water Power #2 <<<<

>>> Vertical shaft water-wheel <<<

In our discussions of ancient water-power, we find that there are essentially three basic types of water-wheels. Of these three, the first that we will take up for discussion will be the vertical shaft water-wheel. The shaft being vertical, rather than horizontal, means that such a power source could be used directly from the shaft requiring no further machinery or gearing to turn a set of mill-stones. This advantage is off-set by the following requirements;

>> The water-fall must be at least some 10 to 12 ft (3 m) in order to turn the wheel. The blades in the wheel are set to an angle of about 30 degrees to the vertical, to catch the water flow;

>> The water flow must be directed through a wooden trough which is set at a steep angle, so that the water will strike the angled blades with great force and speed;

>> On occasion, a pit can be dug to accommodate this arrangement, however if such is the case;

>> Some sort of channel below the pit would have to be excavated or built in order to drain the water away, after leaving the water-wheel.

>> The water-wheel itself, would be lying in a horizontal position and would require some sort of platform on which to rest and rotate freely. Depending on the size of the wheel this would require the wheel platform and flow conduit below the wheel to be lower that the fall distance for the water.

We have locally in our small town, a sawmill, which can also grind grain, and be rigged to cut shingles. It is powered by a vertical shaft water-wheel which dates from the late 1700’s. However, one of the problems with the mill is that it can only run when the mill pond is completely full. When the level of the millpond drops because of a lack of a sufficient water supply, the distance for the water-fall is decreased, and the water can no longer turn the wheel which powers the sawmill.

This situation needs to have a significant fall of water from the water supply to the water-wheel, and enough room below the mill structure for the water-wheel and platform to be installed and the runoff trough to be built.

Respectfully Submitted;
Marcus Audens
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