Fig. 34.
Fig. 35.
Fig. 36.
An important point in the economy of the Argand lamp, is the level at which the outlet for the oil, in its passage from the fountain to the burner, should be cut. The cutting of this hole (generally called the flow-hole) in the pipe is termed the Flowing of the Lamp. flowing of the lamp, and is commonly done by successive trials, until the oil stands at the proper level of the burner, before the wick is put in. A more ready and accurate method of accomplishing this object and at once determining the level at which the flow-hole should be cut, was introduced by Mr James Murdoch, the Foreman of Lightroom Repairs to the Scotch Board, and is generally employed in the Northern Lighthouses. Its nature will be readily understood by a reference to the accompanying diagram, [No. 37]:
Fig. 37.
