Another sharing for the day from the Blue House of Via-HYGEIA, in which we continue our discovery of Albert de Rochas’ 1884 ‘La Science dans l’Antiquité, les origines de la Science’, published by Georges Masson in Paris, with a new excerpt, ‘Hero Of Alexandria’s Oil Fountain Lamp’. From page 112 to 114.
‘…The same writers also indicate diverse process to manufacture portable lamps in which the oil rises automatically. The most ingenious of those is the one today know as ‘Hero’s Fountain’. Here is the text of the Alexandrian engineer:
“The making of a candelabra, such that, when the oil is consumed, there is some gushing from the handle, in the quantity one desires, and that without the need to place above a vase, used a an oil tank, for refill. ( See below illustration 47).
One need to manufacture a hollow candelabra, with a pyramidal base. That is to say, ABΓΔ (ABCD) the pyramidal base, and inside this base, a wall (cloison) EZ. That’s to say also HΘ the rod of the candelabra that needs to be hollow too; above it a cup KΛ is placed that could contain a great quantity of oil. From the wall (cloison) EZ a tube MN that crosses it and emerges almost at the lid of the KΛ cup upon which a lamp is placed, in a manner that there is some room for air. Another tube ΞO goes through the KΛ lid, drops, on one hand way down to the bottom of the cup (in a manner that allows a liquid to flow), and on the other hand forms a slight protrusion on the lid. To this protrusion another tube Π is carefully adjusted, clogged at the top and that crosses the bottom of the lamp, becomes one with it et is found enclosed in its entirety in the inside of the lamp. To the tube Π another finer one is welded to communicate with it and stretches to the extremity of the lamps’ handle; this tube arrives in the handle in a manner that it is able to pour inside the lamp, itself having an opening of the average size.-under the wall (cloison) EZ a tap is welded that goes inside the ΓΔEZ tank in a manner that, when open, the water of the ABEZ tank gushes into the ΓΔEZ tank. In the above plaque AB a hole is pierced through which the ABEZ tank can be filled by water; the air contained inside escapes through the same way. Now, let’s take the lamp away and fill the cup with oil with the tube ΞO; the air will escape through the MN tube and then by a tap that is opened at the ΓΔ bottom, when the water that the ΓΔEZ tank may contain has flowed away. Put the lamp back on its foot in adjusting it to the Π tube; when the need to pour oil will come, the tap which is near the EZ wall (cloison) will be opened, and the water that is contained in the ABEZ tank will flow down into the ΓΔEZ tank and the air inside it will be repelled by the MN tube into the cup, allowing the oil to flow up; it will flow into the lamp by the ΞO tube et the one that prolongates it. When one would want to stop the inflow of the oil, the tap is closed et the flowing ceases. This can be repeated as much time as needed.”
This was, perhaps Plato’s lamp, which Athenaeus tells us about in his ‘Learned Banqueteers’, or ‘Deipnosophistae’, and how it provided light to the famous philosopher during the long nights of the year.’
A Via-HYGEIA note: Here Albert de Rochas is confusing ‘Plato the Philosopher’ with ‘Plato the comic playwright’ who in his play, ‘The Long Night’ describes Hero’s oil fountain lamp:
“…And Plato in the ‘The Long Night’ (fragment 90): ‘There at the highest point of his temple he’ll have a ‘luchnos’ ( λύχνος, a portable lamp) with two oil chambers.’ ” (Source: ‘Deipnosophistae’, chapter XV, 700f-701)