Primary winding

“ Winding is much less irksome if a piece of tubing is interposed between the spindle and the other hand, which can then maintain a firm grip without exercising a braking effect.
This kind of winder is unsuited for reeling in a string on which there is a heavy pull, as the hands are working at a great disadvantage at certain points of a revolution.
[Illustration: FIG. 123.—Plan of string-winding drum, frame, and brake.]
A far better type is shown in Figs. 123 and 124. Select a canister at least 6 inches in diameter, and not more than 6 inches long, with an overlapping lid. ”

“ Wind the Motors Slowly, especially after the first row of knots begin, as it puts the rubber to the least amount of strain by doing this. Quick winding not only strains the rubber but makes the knots form in bunches, and uneven winding, of course, produces an uneven unwinding. ”

“ Evidently, if the spring is strong enough to more than lift the leg, a loss of power will159 result, since the rider would have to hold it in check even in coming up in order to keep it from stopping with a bang, as is sometimes noticed when he jumps from a treadle machine. The winding and unwinding of the spring involves no loss of power except in heat incident to motion and imperfect elasticity, which is quite small. ”

“ If the ratio of the winder is 5 to 1, that is if the rubber is twisted five times to every revolution of the main wheel of the winder, 100 turns of the winder will be sufficient for the first trial. This propelling power can be increased as the trials proceed. When the winding has been accomplished the rubber hooks should be detached from the winder hooks and attached to the hooks at the front of the side members as shown in the diagram. ”

“ A concentrated winding is one in which the armature has only one tooth per phase per pole, that is, the number of teeth equals the number of poles. A concentrated winding of the half coil type has only one side of a coil in each slot as in fig. ”

“ Wind on a smooth, even layer of wire, permitting each turn to touch the other, but none to lap over. Carry the winding to within one-half inch of the ends of the insulating tube and then wind on two layers of the waxed paper. ”

“ Walking rapidly now, and with her eyes wide-open, she distinctly saw in the air before her what was not there a moment ago, a winding-sheet,—cold, white, and ghastly, waved by the likeness of four wan hands,—that rose with a long inflation and fell in rigid folds, while a voice, shaping itself from the hollowness above, spectral and melancholy, sighed,—"The Lord have mercy on the people! The Lord have mercy on the people!" ”

“ The governing is entirely automatic. If the pressure on the wind wheel, which it will be seen is set off the centre line of the mill and tower, exceeds that found desirable—and this can be regulated by means of a spring on the fantail—the windmill automatically turns on the turn-table and presents an ellipse to the wind instead of a circular face, thus decreasing the area exposed to the wind gradually until the wheel reaches its final position, or is hauled out of gear, when the edges only are opposed to the full force of the wind. ”

“ The arguments founded upon such a view of the case, generally assume some such form as the following--"It is true you can accomplish such or such a rate of motion; but that is only in a room, with a calm atmosphere, or with a favourable current of wind. In the open air, with the wind at the rate of twenty or thirty miles an hour, your feeble power would be of no avail. You could never expect to direct your course against the wind, and if you were to attempt it and the wind were strong, you would inevitably be blown to pieces by the force of the current." ”

“ To give some idea of the wind's power, as shown in a larger way, one of the lifeboats on the after skids was up-ended against the mizzen-mast, and there crushed flat by the wind, as though a monstrous invisible hand had pinched it. Does this help you a little to gain an idea of wind-force never met with in a thousand ordinary lives? ”

“ I had often noticed that, in the severest storms, seabirds would remain poised in the air without moving a wing, facing the wind, and yet not recede before it, but by a slight motion of the wings, not up and down or a stroke, but a sort of elevation of the body, dart dead to windward against it. I had also noticed that, if a tin plate was thrown into the air against a strong wind, it would often, if at the right angle, increase its speed greatly after leaving the hand, and dart into the wind's eye with extreme velocity. ”

“ These are the causes above and below ground which are at work. By compression they rouse the winds; they strive in narrow gorges; in that close strife their channel strangles them. As when a wave, drawn up again and again from the deep, has drunk full of the East Wind's violence, the billows redouble their number and the first are pushed on by the last, in that same way the (volcanic) wind feels the impact of the struggle which compresses it, wraps its own strength within its heavy mass and impels its close-packed particles through fiery passages. ”

“ The fact is that the wind is continually varying in force, and while the ordinary pressure plate is admirably adapted for measuring the force of a steady and uniform wind, it is entirely unsuitable for following the rapid fluctuations of the natural wind. To make matters worse, the pen which records the motion of the plate is often connected with it by an extensive system of chains and levers. A violent gust strikes the plate, which is driven back and carried by its own momentum far past the position in which a steady wind of the same force would place it ”

“ If she is inclined to "fall off" too much, and run before the wind, the jib-sheet stretches, the wind spills out of the jib, and the pressure upon her aftersails quickly brings her up on the wind again. ”

“ From Table V it will be seen also that a wind velocity of fifteen miles per hour develops a power three times as great as an eight-mile wind, and a twenty-mile wind is twice as powerful as a fifteen-mile, or six times that of an eight-mile. Hence, a small increase in velocity greatly increases the power of the windmill, while a low velocity gives but little working force. ”

“ Every wind that blows is an instance of the pneumatic transmission of power, and every windmill or sail that catches the breeze is a demonstration of it. The modern or technical use of the term, however, is confined to the compression of air at one point and its transmission to another point where it is used in motors to do work. ”

“ Dismissing the old windmill and the æolian wheel as not fully coming up to the mark, M. Plessuer turns to sails as affording a possible solution of the problem. "The utilization of the power of the winds," he writes, "and its transformation into mechanical work are only possible by means of sailing vehicles, driven by wind upon a circular railway, the power generated by such rotation being transmitted to an axle and thence to machinery." ”

“ The useful power developed by windmills when pumping water in a moderate wind, say of sixteen miles an hour velocity, is not very high, ranging from one twenty-fifth horse-power for an eight and one-half foot wheel to one and one-half horse- [Pg 42] power for a twenty-five foot wheel. The claims of some makers of windmills as to the power developed should be accepted with caution. ”

“ The lower atmospheric strata are retarded by friction against the earth, and the upper ones by those immediately below them; the velocity of translation, therefore, in the case of wind, increases from the ground upward. This difference of velocity tilts the sound-wave upward in a direction opposed to, and downward in a direction coincident with, the wind. ”

“ To suppose, as many do, that regular winds, arising from constant and extensive causes, can come into bodily conflict and preserve their identity and original impetus for days, without immediate and strongly impelling forces to sustain their motion, implies a profound ignorance of mechanical science, and is little better than those ancient superstitions which gave a personal identity to the winds. The momentum of ordinary winds is a feeble force in comparison with those forces of pressure and friction which continually modify it. ”

“ Jardine was unceremoniously urged.
"Does the wind affect the safety of the machine?" he asked solicitously, gazing aloft as well as he could through the slender steel spokes to where the topmost laden settees were swinging back and forth, seemingly with added impetus in the stiff breeze. ”

“ Hence, what would simply be a north or south wind but for the earth’s rotatory motion, becomes a north-east and south-east wind as it approaches those regions where, the velocity of the globe being so much greater than where it originated, it lags behind it in its easterly course. ”

“ When we expose the sails of a windmill obliquely to the gale, we check the velocity of a small portion of the atmosphere, and convert its own rectilinear motion into one of rotation in the sails; we thus change the direction of force, but we create no power. ”

“ It is evident that if a bird can, by altering its angle and altitude, so manipulate the wind coming within its grasp, that the portions that are moving in excess of the mean velocity have their velocity reduced, and those that are moving at less than the mean velocity are accelerated, the total energy of the wind will be reduced, and the energy thus taken from the wind may become available for the purposes of propulsion. ”

“ There are certain winds, called trade-winds, the theory of which may be easily explained on the principle of rarefaction, affected, as it is, by the relative position of the different parts of the earth with the sun at different seasons of the year, and at various parts of the day. ”

“ It was first utilised in windmills, whose sails are nothing more nor less than an immense screw which is turned by the action of the wind on its surface. In the case of turbine water-wheels, where perhaps 970 cubic feet of water are utilised by means of a mechanism not larger than a hat, we see another illustration of it, with this difference, that water takes the place of wind as the motive power. ”

“ It is evident that this place of meeting will recede before the stronger wind, until the momentum of the stronger wind is so diminished by resistance, and its strength so reduced as exactly to be counterbalanced by the weaker wind. ”

“ When the wind is gusty the moment of inertia of the moving parts of the instrument necessitates an appreciable correction; thus, when the gust is at its height the revolving parts receive an impetus that lasts after the gust has gone down, so that the actual velocity of the cups is too high. For this reason, also, comparisons and studies of anemometers made in the irregular natural winds of a free air are unsatisfactory. ”

“ All nature seems frozen to death, the winds included. Unfortunately, we have no reliable data for the parallels beyond, and do not know, therefore, whether easterly winds are the prevalent winds or not. It is probable, as we approached the pole, that we should find another calm. The winds, [see the arrows,] as they come hurrying along the circle, from its northern segment, bring with them an impetus toward the east, derived from the diurnal motion of the earth, on its axis. As these winds approach the pole, this velocity increases, in consequence of the diminishing diameter of the parallels. ”

“ The light steel windmills tremble throughout their frames and tug at their moorings, as they vibrate in the wind that often blows from one week's end to another across that high, active, resolute stretch of country. ”

“ A windmill consists of a series of inclined planes, each of which forms one of the radii of a circle, or spokes of a wheel, to the axle of which a gearing is adjusted by which the power generated is utilized. The wheel is made to face the wind by the wind itself blowing against a sort of rudder which projects from the axis. The wind blowing against the inclined surfaces or vanes of the wheel causes each vane to move in accordance with the law of component forces, thus revolving the wheel as a whole. ”

“ The utility of the wind, however, in generating the power in a stationary mechanism is familiar to everyone. Windmills were constructed at a comparatively early period, and notwithstanding all the recent progress in the development of steam and electrical power, this relatively primitive so-called prime mover still holds its own in agricultural districts, particularly in its application to pumps. ”

“ A windmill or a weather-vane points toward the source of the wind, obviously not because either exercises any special choice in the matter, but because it is constructed on such lines of symmetry that when the wind strikes it, if it slants the slightest to left or right, the more exposed surface receives the greatest pressure and thus swings the body back into the line of least resistance. ”

“ The modern windmill, acting on precisely the same principle, is a comparatively small affair, comprising many vanes of metal, and constituting a far more practical machine. The great defect of all windmills, however, is found in the fact that of necessity they furnish such variable power, since the force of the wind is incessantly changing. Worst of all, there may be protracted periods of atmospheric calm, during which, of course, the windmill ceases to have any utility whatever. ”