Various

“ A cold, damp wind makes the passengers hurry into the carriages, and strikes us sharply as we step on to the foot-plate of the engine, which has just joined the train. But as we get behind the shelter of the screen, we feel a generous and slightly unctuous sensation of warmth very comforting to a chilly man. The brasswork of the engine shines brilliantly, the footboard has been newly scrubbed, and the driver and stoker stand waiting for the signal. The needle shows that the steam is just below the pressure at which it would begin to blow off ”

“ We walk past the train, laden with miserable sea-sick humanity, and step on the engine, which stands in the dark at the end of the platform. Time is up, and we pass from the dim half-light of the station into outer darkness. ”

“ A gentle application of the brake pulls us up, and the journey is over. It is difficult to realize, as the engine stands quietly under the lee of the pier while the driver examines the machinery, and the fire, burned low, throws out a gentle warmth as we stand before it, that half an hour ago we were tearing along the line at full speed, while the foot-plate that is now so pleasant to lounge on throbbed beneath us. ”

“ A blacker night there could hardly be; looking ahead there is nothing to be seen but one's own reflection in the weather-glass. We are in the midst of obscurity, which suddenly changes to a rich light as the whistle is opened and we enter a tunnel. ”

“ The moon is seen fitfully through the whirling steam; the surrounding country is visible for miles round. The effect produced is unspeakably beautiful. In the mean time let us turn our attention to the working of the engine. In the first place, let us take note that, although the engine we are now on, and that which took us from London, belong to the same type, their performances are somewhat different. No two engines ever resemble each other, no matter how carefully they may have been built from the same plan, neither do any two drivers manage their engines precisely in the same way. ”

“ Over it all we advance, the engine laboring and puffing on one or two heavy gradients, in spite of a full supply of steam, or tearing down the inclines with hardly any, or none at all and the brake on. And here it may be noted that, like modern men, modern engines have been put upon diet, and are not allowed to indulge in so much victual as their forefathers. The engine-driver, like the doctor of the new school, is determined not to ruin his patient by over-indulgence, and will tell you severely enough that "he will never be guilty of choking his engine with an over-supply of steam." ”

“ Far ahead we see a white speck, which increases in size till the fierce light from the fire pales, and we are once more in open day. The weather has lifted, the sky is gray, but there is no longer any appearance of mist. The hills on the horizon stand out sharply, and seem to keep pace with us as the miles slip past. ”

“ The tender and guard's van glow in the light thrown by the fire, trees and houses by the side of the track stand out sharply for a moment and are then lost to sight, the light from the carriage windows produces the effect of the wake of a ship seen from the stern. Gradually the clouds have rolled away, leaving the sky clear. ”

“ The power to generate a current is temporarily weakened by sending a battery current through the cell while exposed to light, in either direction. The current generated by exposure to light is also weakened by warming the cell, unless the cell is arranged for producing current by exposure to heat.
The properties of sensitiveness to light and to change of battery power are independent of each other, as I have cells which are sensitive to change of current but absolutely insensitive to light—their resistance remaining exactly the same whether the cells are in darkness or in sunlight. ”

“ It is pleasant from our seat in the corner of the screen to see this preparation for the work ahead—the absolute calm of driver and stoker, who exchange no word, but go steadfastly and quietly about their business; to feel the vibrations from the rails beneath throb through one with slowly increasing rapidity, or watch the trees and houses go past as gulls flap past a boat. For there is a certain apparent swagging movement of the objects past which one travels which can only be likened to the peculiar flight of a large sea-bird. ”

“ The current appears instantly when the light is thrown upon the cell, and ceases instantly when the light is shut off. If the light is varied properly, by any suitable means, a telephonic or other corresponding current is produced, which can be utilized by any suitable apparatus, thus requiring no battery but the selenium cell itself. The strength of the current varies with the amount of light on the cell, and with the extent of the surface which is lighted.
I produce current not only by exposure to sunlight, but also to dim diffused daylight, to moonlight, and even to lamplight. ”

“ It is the driver's principal object to get the required amount of work out of his engine with the smallest possible expenditure of coal and water. To obtain this result the steam must be worked expansively, which is done by placing the valve gear in such a position by means of the lever that the supply of steam to the cylinders is cut off, as we have stated at the beginning of this article, before the piston has accomplished its full stroke. There are two ways of controlling the speed of an engine worked, as all locomotives are worked now, expansively. ”

“ The spectacle of a little selenium being stimulated, by a few interruptions of the current through it, into changing its resistance from a fraction of an ohm up to a million or several millions of ohms, and repeatedly and instantly changing back and forth, up and down, through such a wide range, we might almost say changing from zero to infinity, and the reverse, instantly, is one which suggests some very far-reaching inquiries to the electrician and the physicist. ”

“ Allowing for differences in the temperature, the currents, and the light, at different times, the resistance of a cell in sunlight will remain practically constant during months of use and experiments, although during that time the treatments received may have varied the resistance in dark hundreds of thousands of ohms—sometimes carrying it up, and at others carrying it down again, perhaps scores of times, until it is "matured," or reaches the condition in which its resistance becomes constant. ”

“ The factors which govern exposure are: the subject of the picture, the lens and its aperture, the rapidity of the plate, and last, but not by any means least, the quality of the light by which the work is to be done.
Let us consider each of these separately, and see if we cannot reduce any of them to rule. In this respect the subject will be found somewhat intractable. Scarcely two subjects will be found to send exactly the same amount of light through the lens. ”

“ When an engine and pump are fitted, the weight is increased from about 80 per cent. in the smaller to 50 per cent. in the larger sizes. An immense advantage attends the use of those distillers that are combined with a winch boiler. Of course, the chief use of the winch is while in dock; some use is made of it at sea to do heavy pulling and hauling, to wash decks, and in case of emergency the circulating pump is used as a fire engine. Were it not, however, for the distiller, the winch boiler would simply be idle lumber at sea. ”

“ A is the supply pipe to admit air to aerate the water; B is the cock where fresh water is drawn off; C is a pipe conveying cooling water to the condenser E, placed on three little feet on top of the boiler, F, whose steam rises up a central pipe to the dome top, where it expands out and returns downward through a number of tubes about 1 in. diameter, in which it is condensed, collected in a bottom chamber, and drawn off through the cock, B. A distiller of this size would make about thirty gallons of fresh water per day. ”

“ In practice, I have been accustomed to find the peculiarities and weaknesses of each cell by trial, developing its strongest properties and avoiding its weaknesses, until, when the cell is finished, it has a definite and known character, and is fitted for certain uses and a certain line of treatment, which should not be departed from, as it will be at the risk of temporarily disabling it. In consequence of the time and labor expended in making cells, in the small way, testing, repairing damages done during experiments, etc., the cost of the cells now is unavoidably rather high. ”

“ When a print upon the ordinary photographic (albumen) paper is wetted, the fiber expands more in one direction than in the other, so that the print becomes unequally enlarged, very slightly in one and much more so in the other way of the paper. When the paper is dried without any strain being put upon it, the fibers regain very nearly their original dimensions and position, so that the distortion which has existed in the wet condition nearly disappears. ”

“ The effect is far more striking than in the daytime. The light is more concentrated, and the mouth of the tunnel we have just entered might be the entrance to Hades—for there is no telltale spot of light to prove to our senses the existence of any opening at the other end. ”

“ In the coal regions of Pennsylvania, a simple, high pressure, single acting Bull engine has been extensively adopted; the dimensions usually run from 36 inches to 80 inches in diameter, and a very common stroke is 10 feet. At the Empire shaft, in the Schuylkill coal region, there is a very fine pair of these engines, with 80 inch cylinders, working 24 inch pumps. The stroke of both steam pistons and pumps is 10 feet. These Bull engines are placed either vertically or on an incline, as is most convenient for the workings. ”

“ In order to obtain these high results, the cells must be protected from light when not in use. The resistance is first measured while the cell is still in total darkness. It is then exposed to sunlight and again measured. It is also necessary to send the current in at the gold electrode or face, as the cell is much less sensitive to light when the light acts upon one surface of the selenium and the current enters at the opposite surface. When the two influences, the light and the current, act through the gold, in conjunction, their forces are united ”

“ It is pretty safe to say that nineteen-twentieths of the coca seen in this market within the past two years must be almost inert and valueless, yet all is sold and used, and its reputation as a therapeutic agent is pretty well kept up. At least many thousands of pounds of the brown ill-smelling leaf, and of preparations made from it, are annually sold. And worse than this, considerable quantities of a handsome looking green leaf, well put up and well taken care of, have been sold and used as coca, when wanting in nearly all its characteristics. ”

“ The current that arrives through L passes through the lightning protector, the body of the commutator, U, the terminal, v, and the call, W, bifurcates at P, and is closed by the earth. The inductor is in circuit, but, as it is in derivation, upon a very feeble resistance, v, nearly the whole of the current passes through the latter. When it is the station that is calling, the call, W, is put in derivation upon the circuit, f2 p, h, so that the portion of the circuit that passes through q W v is exceedingly feeble, and incapable of operating the bell of the post that is calling. ”

“ A "U B cell" is one whose resistance becomes greater as the battery power (or strength of current) becomes less, and vice versa, being Unlike the Battery power, or current strength.
These changes of resistance are not due to heating of the conductor or the selenium, and the following instance will illustrate this. I have one cell in which the selenium has about one-fourth inch square of surface melted on a brass block one inch thick. This cell measured, with 25 elements of Leclanche, 40,000 ohms. ”

“ The distiller, however, finds useful employment for it, and has also this excellent effect, that as steam is pretty constantly kept up for the distiller, in the evil event of a fire the boiler is ready to work at once. In horizontal types of distiller an engine and pump are mounted on a cast iron casing as a bed, and in this casing is placed a number of tubes through which the steam passes to be condensed, the whole being simply a surface condenser with engine and pump above. ”

“ The distiller and filter occupy very much less space than that which would be occupied by the casks or tanks of water otherwise required to be carried.
Coming now a little to detail, sea water distillers are usually fitted in connection with the winch and its boiler, which latter supplies the steam both for distillation and to drive the engine working its circulating pump. Smaller distillers are worked without a pump, the cooling water merely passing through by gravitation. ”

“ We speed by a curve or two, and find ourselves on the sea-shore; one more tunnel, and with steam off we go soberly into the last station. But there is one step more. The breeze blows about our ears. Before us the rails are wet, for the sea swept over them not many hours since, and to accomplish the last few yards of our journey the lever controlling the sand-box must be used liberally, to prevent slipping ”

“ The slope of the main pump is 39 degrees, and the machinery has been designed to raise water from 4,000 feet depth. The pumps are of the usual Cornish plunger type, with flap valves. There is an auxiliary engine, of the Porter-Allen type, for driving the pumps and man engines when the main engine is not working. It makes a 160 revolutions per minute, the same as the rope wheels The seeming complication of the arrangement is due to the fact that it had to be adapted to existing works, for increased depths, and put in without interfering with the daily operation of the mine. ”

“ Our train is timed to start in the small hours, and the night seems dirty and depressing enough as we make our way for a cup of coffee to the refreshment room, where a melancholy Italian sits in sad state eating Bath buns and drinking brandy. ”