Popular Recreation: Magic Lanterns...stage above described must be replaced with a "lime clock stage," as shown in Fig. 5, which arrangement in its entirety I call the "oxy-hydrogen lime clock jet."
…stage above described must be replaced with a “lime clock stage,” as shown in Fig. 5, which arrangement in its entirety I call the “oxy-hydrogen lime clock jet.” The lime cylinder should always be warmed before it is brought under the full action of the oxy-hydrogen jet; and as some limes are apt to crack during use, much to the danger of the condensers, and with inevitable delay to the lecture, it is always well to keep a second lime warm and in reserve. This is simply provided for by making the lime pin longer than usual, so that the reserve may be kept above the incandescent lime cylinder, as shown in Fig. 5. It is well to be provided with a pair of lime tongs, with which to grasp the entire lime cylinder whenever it becomes necessary to remove it from its stage pin.
Gas-holders may be gas-bags, pneumatic gasometers, or condensed gas-bottles. The first are in general use, the second and cumbrous, but being made entirely of metal, are well adapted to use in foreign climates; while the third, though by far the most convenient and portable contrivance, are only employed to a limited extent, through it being…
Extract from The Popular Recreator, Topic: Magic Lanterns, section ii, page 339.