[Fig. 649.] As I find when these screw cups ([fig. 648.]) are used upon beams of engines and moving bearings, that the screw is apt to be tightened by the motion; and also, as I think the action of the screw is uncertain, from the workman neglecting to screw it down sufficiently, it answers best to take out the capillary thread when the lubrication is not required; and to effect this easily, I have a tin top to the cup, with a round pipe soldered to it: this pipe has a slit in it, like a pencil case, and allows a bolt B to slide easily in it. In [fig. 650.] the bolt is down; in [fig. 651.], the bolt, which is a piece of brass wire, is drawn up, and there is no capillary action between the thread and the oil. In [fig. 651.] it will be observed, that the bolt is kept in its place by its head C, resting in a lateral slit in the pipe, and it cannot be drawn out on account of the pin E. One end of the thread is fastened to the eye-hole at the bottom of the bolt, and the other end is tied to a small wire which crosses the lower orifice of the tube at D and which is shown in plan [fig. 652.]
By this simple contrivance the capillary action can be stopped or renewed in a second, without removing the top of the lubricator.
The saving by this plan, instead of pouring oil into the bearings, is 2 gallons out of 3, while the bearings are better oiled.
“I send you the drawings of the lubricators, with a detailed explanation. I have omitted to state, that the saving in labour is considerable where there are many joints to keep oiled three or four times a day; and that the workman does not, with this apparatus, run the risk of being caught by the machinery. Perhaps your friends may be at a loss how to tie on the cotton or worsted thread. I pass a long thread through the eye-hole E of the bolt, and then draw the two ends through the tube by a fine wire with a hook to it, one end on one side of the cross wire D, and the other end on the other side. I then put the cover on, and the bolt in the position shown in [fig. 651.]; when by drawing the two ends of the thread, and tying them across the wire D, you have the exact length required. When you wish to see the quantity of oil remaining in the lubricator, the bolt must be dropped as in [fig. 650.], and you can then lift the cover a little way off, without breaking the thread, and replenish with oil. The cost of [fig. 650.] in tin plate is 9d. The figures in the wood cuts are one third of the full size.
“Believe me to be yours sincerely,
“E. J. Woolsey.”
LUPININE, is a substance of a gummy appearance, so named by M. Cussola, because it was obtained from Lupines.
LUPULINE, from Humulus Lupulus; is the peculiar bitter aromatic principle of the hop. See [Beer].
LUTE (from lutum, clay; Lut, Fr.; Kitte, Beschläge, Germ.); is a pasty or loamy matter employed to close the joints of chemical apparatus, or to coat their surfaces, and protect them from the direct action of flame. Lutes differ according to the nature of the vapours which they are destined to confine, and the degree of heat which they are to be exposed to.
1. Lute of linseed meal, made into a soft plastic dough with water, and immediately applied pretty thick to junctions of glass, or stone-ware, makes them perfectly tight, hardens speedily, resists acid and ammoniacal vapours, as also a moderate degree of heat. It becomes stronger when the meal is kneaded with milk, lime-water, or solution of glue.
2. Lute of thick gum-water, kneaded with clay, and iron filings, serves well for permanent junctions, as it becomes extremely solid.