String course

“ Now, since it has been shewn that bodies begin to run down equal descents with equal velocities, it follows that the weight on the short string and that on the long string must commence to move down the concentric curves of their respective arcs at an equal rate. ”

“ By relaxing one of the strings, it is thrown out of unison with the other, and then all efforts to unhorse the riders are unavailing. That accumulation of impulses, which unison alone renders possible, cannot here take place, and the consequence is that, however great the agitation of the one string may be, it fails to produce any sensible effect upon the other. ”

“ It has gained speed in the direction of the sun, but this has operated to increase its rotational speed. Thus it has gained a greater centrifugal force—you can see the effect with a bit of chalk on the end of a string. The smaller the circle it swings in, the greater the tendency to fly outward. But as long as we continue the force that was added to draw it in, it will remain in equilibrium. ”

“ A large quantity is in this manner manufactured in an incredibly short time. The rushes are then cut to the desired length, and laid out on the ground singly, and in a row, when holes are made, at intervals of about two inches, through each rush, and the string in question passed through them by means of a bone or thorn needle. ”

“ Inconvenience is, that oftentimes, if a High-stretch'd small String happen to slip down, 'tis in great danger to break at the next winding up, especially in wet moist weather, and that It have been long slack. The 4th. is, that when a String hath been slipt back, it will not stand in Tune, under many Amendments; for it is continually in stretching itself, till it come to Its highest stretch. ”

“ There are two distinct methods of investigating the motion of a uniform stretched string. One of these may be called the wave method, and the other the harmonic method. The wave method is founded on the theorem that in a stretched string of infinite length a wave of any form may be propagated in either direction with a certain velocity, V, which we may define as the “velocity of propagation.” ”

“ It is evident that all this theory applied to one obstruction is simply repeated in a number of them, and a number of them make up a rough road, bearing in mind that a rut is but one form of an obstacle.
Some makers of late seem to realize the importance of springs which will allow of a horizontal as well as a vertical motion, and have in them not only provided against the loss of momentum in the man, but also in the entire machine exclusive of the front wheel. ”

“ After moving at a rate of about twenty-five to thirty miles an hour with reference to the wind, or ten to fifteen miles over the ground, the machine, while keeping its course parallel to the slope, increased its speed, thus indicating that it could glide on a slope less steep. ”

“ If a definite total run is specified the tread must be figured. (4) Since there is always one more riser than tread, the run per step is obtained by dividing the total run in inches by the number of risers less one. The numbers thus obtained for rise and run per step are the ones to be used on the framing square in laying out the stringers.
Fig. 122. Laying out String Fig. 123. Pitch Board. Fig. 124. Economical Center Stringer
(5) Joint one edge of each stringer straight and square and place the framing square as in Fig. 122 and scribe along both blade and tongue. ”

“ Take a string made up of pieces alternately black and white, each exactly as long as the wheel is high, and stretch it between the mark and the top of the wheel. If there are n pieces of string included, the slope is 1 in n, for by similar triangles the diameter of the wheel is to the length of the string as the vertical rise is to the distance on the road. This gives the average steepness of a piece sufficiently long to be worth testing, because an incline only a few feet in length, of almost any steepness, can be mounted by the aid of momentum. ”

“ Boys are liable to make a mistake in getting their string too short, so it must be measured. I place a couple of nails one hundred feet apart in the rail of the board fence, the boys wind about that until they have the required length, and by counting the string I can soon see if it is correct. If the string is given back to the boy, there is a temptation to take out some. There is no disadvantage in letting out the string from a stick in the races, if there is a reel to attach it to when it comes to the winding in. ”

“ A very strong chain is hooked, one end to the body of the stump, or its principal root, and the other to the axle-tree. The power of horses or oxen is then applied to the loose end of the rope above-mentioned, and as they draw, rotary motion is communicated, through the smallest wheel, to the axle-tree, on which, as the chain hooked to the stump winds up, the stump itself is gradually disengaged from the earth in which it grew. ”

“ For in these Cross-Peals we must observe the prime Movement, which sets the whole Frame a going, and that is called the Hunt, which hath One constant Uniform Motion throughout the Peal, and different from that of the other Notes; and indeed by this the whole Course of the Peal is Steered. This keeps a continual motion through the other Notes, i. e. From Leading, to strike behind, and from thence again to Lead; which is called one compleat Course.
Some Peals upon five Bells consist of single Courses, wherein are ten Changes, and twelve Courses make the Peal. ”

“ Therefore if a body either oscillates by hanging to a string, or by any polished and perfectly smooth impediment is forced to move in a curve line; and another body ascends or descends in a right line, and their velocities be equal at any one equal altitude ”

“ Over the navel, nature had built a bridge, above which four strings were drawn. The whole machine rested on a single leg, so that their motion was a spring rather than a walk. Their activity was very great, and they jumped with much agility over the fields. ”

“ The one at the top marks the points at the distance each line is required to be from others. The string being chalked either black or white,—according as the line has to show upon a light or dark ground,—he holds it to one of the points, and lets fall the weighted end, which, when quite steady, the person who is below strains tight, and raising the string between his finger and thumb in the middle, lets it fall back sharply on the wall. ”

“ The effect of a propelling surface in the form of a screw, and moving at a certain velocity, as compared with an equal surface moving at the same velocity but applied in the shape of paddle-boards, having been ascertained, it remains to determine the comparative power required to give motion to that surface. ”

“ In Plate 5, Fig. 12, A X represents a Crank or Handle with a variable radius, the intent of which is to adapt a man’s strength to the velocity and intensity of any resistance he may have to overcome. The manner is this: B is a Screw pressing on the quadrant, and fixing the arm C X to any required angle with the part A C: thus determining the virtual radius of the handle. ”

“ Except at certain exceptional points the velocity will be greater as the slope of the bed is greater, and, as the velocity and cross section of the stream vary inversely, the section of the stream will be least where the velocity and slope are greatest. If in a stream of tolerably uniform slope an obstruction such as a weir is built, that will cause an alteration of flow similar to that of an alteration of the slope of the bed for a greater or less distance above the weir, and the originally uniform cross section of the stream will become a varied one. ”

“ Hence ripples, formed by a current are always moving and are unsymmetrical on the cross-section, presenting a long, gentle slope toward the current, and a short, steep slope away from it, the arrow in the figure indicating the direction of the current, or of the sea in the case of a beach. ”

“ In most artificial channels the form of section is constant, and the bed has a uniform slope. In that case the motion is uniform, the depth is constant, and the stream surface is parallel to the bed. If when steady motion is established the sections are unequal, the motion is steady motion with varying velocity from section to section. Ordinary rivers are in this condition, especially where the flow is modified by weirs or obstructions. ”

“ If we hold in our left hand a bundle of parallel strings, we can with our right hand turn these round and round, thus imitating the revolving movement of a twining plant, and the strings do not become twisted. But if we hold at the same time a stick in our left hand, in such a position that the strings become spirally turned round it, they will inevitably become twisted. ”

“ From ledge to ledge rushes the stream, making falls innumerable, decked with living fringes of foam, and as the noisy current hurries onward it engirdles the boulders with foamy rings, or hangs upon them a long white train that flutters and glistens as sunbeams drop down through the wind-shaken leaves. ”

“ Over trestles a hundred feet high of frail and creaking timbers we rush without the least uneasiness or anxiety, for the machine and train being behind us and unseen we do not realize that hundreds of tons are being whirled over the frail bridge-work, and forget that there is anything heavier upon them than our own weight; onward we slide; a turn brings us face to face with a mighty precipice; we are rushing headlong against the rocky barrier when a sudden bend around a jutting point, reveals before us a hole in the rocky mass ”

“ Now if a coloured streak be painted (this was done with a large number of twining plants) along, we will say, the convex line of surface, this coloured streak will after a time (depending on the rate of revolution) be found to lie along one side of the bow, then along the concave side, then on the opposite side, and, lastly, again on the original convex surface. This clearly proves that the internodes, during the revolving movement, become bowed in every direction. The movement is, in fact, a continuous self-bowing of the whole shoot, successively directed to all points of the compass. ”

“ A piece of string is to be wound round the groove, a hole being made in the centre of the wood, through which the end of the string has first to be secured. In playing with the toy, the loose end of the string is to be held between the forefinger and thumb, and the grooved piece of wood is to be let fall. ”

“ The fourth argument is that concerning the two rows of bodies, each row being composed of an equal number of bodies of equal size, passing each other on a race-course as they proceed with equal velocity in opposite directions, the one row originally occupying the space between the goal and the middle point of the course, and the other that between the middle point and the starting-post. ”

“ By contracting the width of the stream the velocity is increased beneath the arches, the same amount of water being obliged to pass through a smaller space, and when the bottom is of such a nature as to yield to this action, there is danger of the foundation being undermined. ”

“ We have here strings, bridge, and sound-board, or belly, as it is technically called, indispensable for the production of the tone, and indivisible in the general effect. The proportionate weight of stringing has to be met by a proportionate thickness and barring of the sound-board, and a proportionate thickness and elevation of the bridge.
The tension of the strings is met by a framing, which has become more rigid as the drawing power of the strings has been gradually increased. In the present concert grands of Messrs. Broadwood, that drawing power may be stated as starting from 150 lb. ”

“ The rate of subsidence of the plant-holder, by which the balance is obtained, is strictly proportional to the rate of rotation of the vertical spindle and the attached train of clock-wheels. A striker is attached to one of the wheels, and a bell is struck at each complete revolution. ”

“ As the spring has very little tension in this position, and as it requires a considerable movement in order to give it tension, the arms c, c, and the bar b, b, are very easily pushed backwards, but as the distance through which they travel increases, the angle of the lever changes and the tension of the spring increases at the same time, so that when the disc is pushed backwards to any considerable distance, a strong resistance is encountered. ”

“ A STRIDE is an act of progressive animal motion, which, for its completion, requires all of the supporting members of the body, in the exercise of their proper functions, to be consecutively and regularly thrust in the direction of the movement until they hold the same relative positions in respect to each other as they did at the commencement of the notation. In the bipedal walk or run a step is one-half of a stride or full round movement. ”

“ On turning the wheel, and properly regulating both the tension and the rapidity of rotation, the beaded cord may be caused to rotate as a whole, and to divide itself successively into 2, 3, 4, or 5 ventral segments. When we envelop the cord in a luminous beam, every spot of light on every bead describes a brilliant circle, and a very beautiful experiment is the result. ”

“ The variation in the length of crank produces an effect comparable to the change of gearing in so far as the distance through which the feet travel in covering a certain distance is concerned, but the difference lies in this, that altering the crank means a given number of revolutions in a circle of varying radius, while altering the gearing means a variable number of revolutions in a circle of given radius, in order to cover a given length of road. ”