Lampas, or Descriptions of Mechanical Improvements of Lamps and Waterpoises

[The vapors] that emerge from the wick are gradually dissolved The author uses "dissolved" to mean what we now call combustion—the chemical breakdown of fuel in the presence of oxygen. rather than all at once. The parts of the flame that are lowest, around H, have a kind of faint blue light until they reach I. At that point, they seem to have their brightest and clearest light and heat. These vapors are not heated to that degree when they first break out; instead, they acquire more heat afterward through the further action of the air upon them. At I, they seem to reach their highest level of dissolution, and from there upward, they become one with the dissolving air, so that they are not detectable to the observer's eye except by other means. Thus, the shining part of this conically shaped space of the flame is only the outside of the cone. It is the area where the surrounding original: "Ambient" air acts upon the ascending emissions of the oil—specifically, where the chain of small circles referring to a diagram not pictured here intercepts the curved lines of the motion of the rising emissions.

This figure and shape of the flame and vapors may be plainly seen with the help of a metallic concave mirror original: "Metalline Concave" placed at a certain distance and position. It can also be seen by observing the shadow of the candle cast by the sun's rays upon a sheet of white paper or a white wall. However, using a concave mirror original: speculum is incomparably better because it so clearly shows the form and behavior of the vapors rising above i i i i, as around k k k k, and so on.

The air—after it has performed the action of dissolution and is saturated and combined with the parts of the oil at i i—ascends through k k k, but it does not shine. None of the vapors or emissions of the oil coming out of the wick at f f f shine between the wick f f and i i. Instead, they begin to be dissolved and to shine as they approach the fresh air at i i, where the dissolution is completed.

The upper parts of the flame shine more than the lower parts. This is because those parts have been heated to a much higher degree by the longer path they have traveled through the hot, hollow original: "Concave" center of the flame, being adjacent or very near to its glowing sides at i i i.

All the lower parts of the wick neither shine nor