Slider

“ The plan is as follows:—The negative to be reproduced is placed in a slider at one end (a) of a camera or other box, constructed to exclude the light throughout. The surface prepared for the reception of the positive—whether albumen, collodion, or paper—is placed in another slider, as usual, at the opposite extremity (c) of the box, and intermediately between the two extremities (at b) is placed a lens. The negative at a is presented to the light of the sky, care being taken that no rays enter the box but those traversing the partly transparent negative. ”

“ The weight w causes any play between the slider and the cross slide to be taken up in the same direction as the tool pressure would take it up, hence the cut taken is a very smooth one. The half-round mandrel being fixed to the lathe face plate will remain true, obviating the liability of the centre of the spherical surface being out of line with the axis of the bearing-bore. ”

“ The cross slider or tool rest of a lathe should be adjusted to closely fit the cross slide of the lathe if true and parallel work is to be bored, because any lost motion that may exist in the slide is multiplied by the length the tool stands out from the tool post. Thus the centre of motion of the rest if it has play, as at b, Fig. 1117, and the direction of motion at the tool point, will be an arc of a circle of which b is the centre, the bend of the tool from the pressure of the cut will have its point of least motion or fulcrum at a ”

“ The office of these sliders, exactly corresponds with that of the levers, in the model above described: for, when lodged in their respective cells, they are upheld, like the levers, by the elastic power of the springs on which they rest; till a pressure superior to that power is applied;—and are again restored to their stations by the reaction of the springs, when the weight, which depressed them, is withdrawn. Each slider projects its side B (as appears in the fifth figure) beyond the spherical surface of the barrel, or frame, which contains it ”

“ Sliderskew was in an ecstasy of delight, rolling her head about, drawing up her skinny shoulders, and wrinkling her cadaverous face into so many and such complicated forms of ugliness, as awakened the unbounded astonishment and disgust even of Mr. ”

“ In the mechanics of making a slide from a negative we have only two methods to consider. If the slide-image is to be the same size as the negative, or a part of the negative, we print by contact, that is, we put the negative and the slide-plate face to face in contact, and we expose to light, the negative being next to the light; this corresponds with making a print on paper. But when we desire to make a slide including all the subject of a negative larger than a slide-plate, or, in fact, when we desire to alter the size of the image at all, we copy the negative "in the camera." ”

“ I just wish there was a slide near Calumet, so that I could take you down and let you see how splendid it is. Why, it's just like—let me see—I've got it! It's just like tobogganing on water. You jump on board the crib at the mouth of the slide, you know, and it moves along very slowly at first, until it gets to the edge of the first slant; then it takes a sudden start, and away it goes shooting down like greased lightning, making the water fly up all around you, just like the snow does when you're tobogganing. ”

“ Pattern 1, plate 11. Begin by the shell. Having smoothed and lined your wood, put a double angular tool (No. 4 of the slide-rest tools) into your rest; turn the slide-screw till the tool is exactly in the centre of your work, when, if you move the wheel round, you will find the tool will only cut a dot. The outer circle is the one with which to commence; turn the slide-rest screw forwards ten whole turns, and you will find you have the circle of the proper size. Now approach the tool to the wood, cut the circle carefully at first, till you decide on the proper depth for the cuts ”

“ The great slide is like common slides in that when once you have started you have to go on to the end—unless you fall down—and then it hurts just as much as the smaller kind on ponds. The great slide runs downhill all the way, so that you keep on going faster and faster and faster. George and Jane went so fast that they had not time to notice the scenery. ”

“ More pictures are spoiled than saved by inexperienced doctoring.
After your chemicals are all prepared, put a plate in your holder, or wooden box with slides, one or more of which accompany every outfit. Focus your camera on some object; a row of buildings, the side of a house, or a board fence is preferable for this experiment. Take off the cap, and pull the slide about half of the way out. Expose about six seconds, and pull out the slide the rest of the way. Expose this six seconds again, and replace the slide. ”

“ As the slide passes along the stock, the string by its own pressure falls into the notch, and is drawn back, together with the slide, thus bending the bow. Still, however much we may work the lever, the string will remain in the notch, and must therefore be thrown out by a kind of trigger. This is self-acting, and is equally simple and ingenious. Immediately under the notch which holds the string, a wooden peg plays loosely through a hole. When the slide is thrust forward and the string falls into the notch, it pushes the peg out of the hole. ”

“ Paint it on your slide, and stop it out all round with asphaltum or any dense black. Then fix to it a simple spiral disk, such as that given in Fig. 2, and the instant the spiral spins the water will begin to flow.
In all designs remember that the fixed slide must be broken up with black and colour, so as not to show the whole of the spiral at once. The wave should, as it were, sweep over the windows. For front designs nothing is superior to a good knighthood star. ”

“ Copy the design through the glass, and it would be as well not to forget that unless you can draw properly on paper you are not likely to do so on a lantern slide, where in the intense light and enlargement every mistake and shakiness of line is exaggerated for the benefit of the spectators. For those who cannot draw, figures of men and animals can be cut out with scissors and pasted on the slide, so as to give a shadow entertainment, as a change from the bought slides. Others can buy transparencies and stick them on for themselves, but the result will never equal hand-painting. ”

“ When the negative is larger than the lantern-slide plate, and it is desirable to reduce the entire view upon the slide, a little extra work will be necessary. Select a room with one window, if possible, and fit a light-proof frame into it to keep out all light with the exception of a hole in which to place the negative, as shown in Fig. 1. Unless this hole is on a line with the sky it will be necessary to place a sheet of white cardboard at an angle of 45 deg. on the outside of the frame to reflect the light through the negative as shown in Fig. ”

“ Two of the cuts show the progress of the performance as seen by the audience. The third cut explains the mechanism. Behind the scenes is a strong frame, up and down which a movable slide works. Tackle is provided to raise and lower the slide; and a workman behind the scenes is intrusted with its manipulation. A bar carrying at its rear end handles, and in front a socket, shown in the upper right-hand corner of the same cut, is journaled in the slide, and can also be thrust in and out through the journal box. ”

“ Slidell was forced against the precipice. But the actual meaning (at which we arrive by guessing) is, that Mr. Slidell was forced against the iron rod. In the words "I was forced with a pressure proportioned to the circumstances of my being compressed into a space," &c. let us again be indulgent, and say as little as possible of the tautology in "pressure" and "compressed." But we ask where are the circumstances spoken of? There is only one circumstance—the circumstance of being compressed. ”

“ Couldn’t leave the trail between the Cache and the bend. Ask any one in the crowd. It’s all straight rock-wall on one side, and there’s been a snow-slide hanging hair-triggered for thirty-six hours on the other. No sane man would sneak out and hide under a slide. And if he had sneaked out, he’d have brought down the slide. I tell you no sane man would try it. ”

“ A clean slide must be selected, all through our pages we emphasise the cleanliness of slides, at or near its centre we put a drop of water and, lifting it with a brush, we place our section in the drop of water. If our examination is to be with a low magnification, we need not use a cover slip, nevertheless it is worth while to cultivate the habit of using one. ”

“ Having focussed our camera and set the stop, we then close the shutter, insert the plate-holder in the back of the camera and carefully draw the slide. Omitting to pull the slide is a common mistake with beginners. We are now ready to decide just what exposure to give our plate. Rules for exposure are almost useless, but in general it may be said that the modern plates are lightning fast and that in bright sunlight at midday the average exposures will not be over 1-25 of a second. ”

“ Referring to the third method, a compound slide rest provides an excellent method of turning tapers whose lengths are within the capacity of the upper slide of the compound rest, because that slide may be used to turn the taper, while the ordinary carriage feed may be used for the parallel parts of the work, and as the tailstock does not require to set over, the work centres are not subject to undue wear. ”

“ A long-legged man, sculling, may use a much longer slide than a short man. But in an eight, if the long man fits his stretcher as if for sculling, he will be doing more than his share, and may be unable to shoot so long a slide through in the required time, except by dint of ‘hurrying’ it; and, if he does this latter, the result is to cripple his swing, as shown supra. There must be a certain amount of give-and-take in arranging slides in an eight or four oar. That length of slide is best which all the crew can work simultaneously and effectively, preserving uniformity of swing and slide. ”

“ It was the spectacle, in earlier days of the slide, of this unorthodox sliding style beating good specimens of fixed-seat oarsmanship which so horrified many of the retired good oarsmen of the fixed-seat school. Before long the true use of the slide became better understood, and thus oarsmen—at all events scientific amateurs—began to realise that, while bad sliding could manage to command more pace than good fixed rowing, yet at the same time good sliding (which will be explained hereafter) will beat bad sliding by even more than the latter can distance good fixed-seat work. ”

“ Sometimes a feed motion to a slide rest is improvised by what is known as the star feed, the principle of action of which is as follows: Upon the outer end of the feed screw of the boring bar or slide rest, as the case may be, is fastened a piece of iron plate, which, from having the form in which stars are usually represented, is called the star. ”

“ Take the slide-rest. It is clearly shown in the French encyclopedia of 1772, see Fig. 3, and even in an edition of 1717. Bramah, Bentham and Brunel, in England, and Sylvanus Brown, [9] in America, are all said to have invented it. David Wilkinson, of Pawtucket, R. I., was granted a patent for it in 1798. [10] But the invention has been, and will always be, credited to Henry Maudslay, of London. It is right that it should be, for he first designed and built it properly, developed its possibilities, and made it generally useful. The modern slide-rest is a lineal descendant from his. ”

“ My papa says there is no difficulty in painting magic-lantern slides with water-color paints, and the design can easily be made without using those dangerous chemicals. He used to make slides in this way when he was a boy: Take a slip of glass of the proper size, and cover one side with a coat of mastic varnish, and let it dry well. Then make your sketch on a piece of white paper, and lay your slide over it, and trace the outlines on the glass with a fine camel's-hair brush and India ink. ”

“ A slide is judged not by what it appears to be when held in the hand, but by its appearance when magnified two to five thousand times on the screen, where a small defect in the slide will show up as a gross fault. ”

“ There are two feed screws—one for operating each boring bar-head, and a spindle for operating the vertical feeds of the bars in the sliding heads. Fig. 728 shows the arrangement for engaging and disengaging the feed nuts of these heads. a is the slide that traverses the rail. It carries a nut made in two halves, n and n′, which are carried in a guide or slide-way, and which open from or close upon the screw f when the handle o is operated in the necessary direction. ”

“ The weather was stormy, and the mountain brook which ran along the slide concluded to waste no more labor in carving out a bed for itself in the rock, when it might as well be using the slide which it found ready made. And one fine day it broke into the slide and half filled it, so that the logs, when they were started down the steep incline, sent the water flying, turned somersaults, stood on end, and played no end of dangerous tricks which no one could foresee. ”

“ If you were to solder a brass-wire ring round the outside of the edge of the tube that carries the front lens, it would make it stronger and easier to regulate the focus, besides giving it a more finished look. If the nozzle and focusing-tube were made altogether of this brass plate it would add to the finish.
[240]
III. How to Make the Slides for a Magic Lantern.
A magic lantern without slides is not of much use. These slides cost a good deal to buy, the price, ranging from two shillings to a guinea, being regulated by the time and skill expended in their production. ”