PROPER SHOEING.
In his article on horseshoeing Mons. Lavalard makes some good points, and also some that appear to me to be erroneous. He says, in regard to the frog, "It is evident, then, that the frog helps the hold, but strange to say, it alone of the three parts has a share in the hold when the hoof is shod."
We see nothing strange about this where horses travel over hard roads; the case is otherwise on soft roads or race tracks. It is easy to make the ground surface of such shape that it will have sufficient hold, without the action of the frog. In the shod foot, the frog has more to do with keeping the foot healthy than assisting in the hold. With horses used for speeding purposes, the frog helps to sustain the sole of the foot, as when the foot is brought down with great force and the road soft enough to receive the imprint of the shoe. He further says that: "Simultaneous with this preservation and regeneration of the frog, the hold of the horse becomes firmer, and more equally divided toward the heels, and when starting a load, there is no clamping with the toe of the hoof, but the foot is brought down flat."
Let us examine this statement and see if the reason why the horse brings the foot down flat is because the frog is good, and has a good hold on the ground. The reason appears to us to be because from the manner of shoeing the horse cannot put his foot in any other way. The shoes are much thinner behind than in front, and the heels pared low enough to insure the frogs resting on the ground. Excessive paring of the heels gives extra length to the shoe, which, being thick at the toe, props the toe up in such a manner that the horse is forced to let the foot remain flat when starting a load. Nothing is gained by keeping the foot flat while starting a load, and to prove this, we ask the reader to observe unshod horses when starting a load. The frog having free access to the ground, see if the horse does not clamp the ground with the toe when exhibiting the maximum of strength. Also examine the imprint of horses' feet (especially the hind ones) when drawing heavy loads over soft ground, and see if the shoe is not pressed more firmly into the ground at the toe than at the heel. This is not because he gets a better use of the frog by so doing, but because the foot is in a better position for the horse to exert his strength without injury to the back tendons. As a further test, place yourself on an incline facing squarely up hill, and see how much power you can exert; then place your feet exactly opposite in direction, and note how much power you can then exhibit. What has made the difference? Simply the relative position of the heels and toes. We do not, like Mons. Lavalard, wish to force our horses to travel up hill all the time, which is the case when shod as he describes.
Horseshoers, like other men who follow a special calling, are apt to think that their theories and practices relating to their special trade are superior to those of other men. I think it is safe to make the assertion, without fear of successful refutation, that there is not more than one horseshoer in ten thousand but what can convince the average horse owner that he (the smith) knows just about all that is worth knowing about horseshoeing.
And the same average horse owner is conceited enough to think himself a better judge of a good job of shoeing than the intelligent animal that wears the shoes till his feet feel as though they were full of thistles. A horse's foot is not a thing that can be cut and slashed into all shapes with impunity, but requires careful as well as intelligent treatment. It is a great mistake to suppose that every sound foot should be treated alike. Each foot has its individuality, which must be recognized and respected if good results are to follow shoeing. It is a lamentable fact, and one that cannot be disputed, that most horseshoers have but a faint notion of what is required to shoe a horse properly, even where no defects exist. If he gets pay for the work, he gives himself no trouble to improve on his methods. But with the owner the case is different. The usefulness and value of the horse are largely affected by the condition of the feet, and he must learn to know how his horse ought to be shod, and then see to it that the work is properly executed. We know from personal experience that this is hard to do. The smith must understand that you are in earnest about the matter, and that you are bound to have your orders obeyed. I have found some men very obstinate, and others always ready to do anything that was an improvement on the old way. First decide what kind of labor the horse is expected to perform. If he is expected to go fast, great care and skill will be required to get everything just as it should be, and don't blame the smith for charging extra for extra work.
It will often be necessary to make several trials before you find out just what suits the horse best, and don't fail to let the horse be judge in the matter, for when he is suited you ought to be.
Place the horse on a smooth, clean floor, and note the set of each foot, and whether it is in line with the limb above it. Cut away the wall of the foot until you come to where it joins the sole; except at the heels and quarter, it may not be quite as low; let the frog and bars remain intact, but see that the shoe will not bear much on the bars. Give the sole about its natural concavity of surface up to the wall, but no further. Place the foot on the floor and see if it is in line with the limb; if not, remove enough horn to make it so. The slant of the front part of the fore foot should, as a rule, be the same as that of the pastern; that of the hind ones a little steeper. Now stand behind the horse while he is made to walk, and see if when the foot approaches the floor both sides come down at the same time so that there is no rocking motion from one side striking first. Disregard the advice of some writers who recommend to have the sole bare on the iron; that theory when put into practice doesn't work worth a cent.
In most cases it will not be necessary to remove much, if any, of the horn from the sole, but there are cases where it will be found necessary to remove quite an amount, or the sole will become so inelastic that it will greatly interfere with the action of the internal organs of the foot. It is evident that nature made the sole of the foot so that it might be acted upon mechanically to remove its surplus growth in the same way as the wall, for in the unshod foot it receives the impact of all sorts of substances, from soft mud to sharp, flinty rocks; and that, too, without becoming dry and brittle.
The bearing surface should be half an inch wide and made positively flat and level, being without lumps or depressions, and not beveled either way unless they are hard and inclined to pinch, when it should be beveled to the outside, so that the weight of the horse when brought upon its surface will cause the heels to open, thereby causing a more healthy condition of the frog. The nail holes of the shoe should be further from the outer edge of the shoe, especially at the toe, than those usually seen in the market. The bearing surfaces of the foot and shoe should be as nearly approximated as possible, else the hoof will be bruised and the shoe soon loosened. The holes being further from the edge, allows the nails to take a deeper and lower hold than is usually given them; the direction of the nails is more nearly across the grain or layers of horn, causing less splitting of its substance, thereby securing a firmer hold upon the foot. Two large nails are usually chosen, 5s or 6s being large enough for ordinary shoes. It is not necessary to hammer down the clinches, if care has been taken to draw the nails, finishing with light strokes of the hammer. The shoes will stay just as long, as we can testify by four years' experience, and the advantages are that the horn is not injured by filing below the clinches nor by the strokes of the hammer during the operation.
Should the horse step upon the shoe, no horn will be removed with the shoe, as is usually done when the clinches are left long and then turned down with the hammer. In such cases, the shoe will be torn off, no matter how solid the clinches hold, and it is better to come away without breaking the hoof. We repeat and make emphatic that the bearing surface of the shoe must not be concave, as it is almost sure to make corns, and induce an inflammatory condition of the foot, and this inflammatory action is the forerunner of the long list of evils that are sure to follow, unless means are taken to relieve the parts. And yet almost every horseshoer in the country gives the bearing surface of the shoe a bevel to the center. Many smiths will deny this, but after they have the shoe ready to apply to the foot, take a square and place the edge across the bearing surface at the heel of the shoe, and ninety-nine times out of one hundred the outside will be the highest.
The front action of a horse may be greatly modified by the weight of the shoe, and here is where great caution, close attention, and a thorough knowledge of the principles involved are required, or one will be liable to throw his horse out of balance if he is used for speeding; for slow work it is better to have the shoe somewhat lighter than the horse might carry than to err in the opposite direction. It is not intended by me to take up all the points of horseshoeing that might be dwelt upon with profit, and no one who reads these remarks will be more ready than I to learn a better method of shoeing than that I now practice, and I sincerely hope that some reader of this paper will favor us with more information on this important subject.—P. D. B., in Wallace's Monthly.
[Milling World].
IDEAS.
By A. Looker-on.
I.
There is yet a good deal to do in successfully applying the roller process to small mills of from 25 to 100 barrels capacity. There has been a great deal done, no doubt, but one thing is lost sight of in all the patents that have been granted so far, and that is cheapness, not only in the price of the machine, but also in its application to the existing or original plant in the mill. It should be of such a nature that as few changes in the machinery as possible should be made.
If a grain of wheat is examined, it will be astonishing to see the chemical laboratory that is locked up in it. The most valuable substances, gluten, is placed near the air and light, while the little cells of the interior are composed of starch, which being the softest is the first to break up under the influence of the rolls. Hence, the flour of the first and second breaks is mostly composed of that substance.
About three and a half per cent. of woody fiber can be removed from a kernel of wheat by a moistened cloth; it is of no value, whatever. The next coating holds nearly all the iron, potash, soda, lime, and phosphoric acid. This wrapper is the granary, so to speak, in which is deposited all the wealth of the berry, and like a good safe is the hardest to open, by either the rollers or burrs.
The use of rolls in cleaning bran is now generally recognized, and they have proved very useful and practical for this purpose especially in large mills. Bran, however, can only be thoroughly cleaned by several operations, and the previous condition of the bran has a great deal to do with the number of operations it has to undergo on the rolls to be well cleaned.
Each passage through the rolls changes the condition of bran, and the oftener it goes through them the lighter and cleaner it becomes, until all the floury portion is removed.
The Austrians use corrugated rolls for the purpose of cleaning bran, the finest being on the last, as in the break rolls. It is more scientific and philosophical to clean the bran in this way than to rub off the flour between burrs in this way than to rub off some of the branny portion as well as the glutinous part.
Rollers for the first cleaning are from eight to ten inches in diameter and from three to five hundred corrugations are used, and this increases up to one thousand for the last rolls used; but fine corrugations wear out soon, and the rolls have to be frequently corrugated or the bran has to be finished on burrs.
The use of rollers is preferable to that of stones for bran, and their use is considered an important advance in milling by most German experts.
As the advantage of the use of rolls instead of burrs consists in the production of a greater amount of middlings, this advantage should be experienced in the cleaning of bran. As the small starchy particles adhering to the bran are separated in the shape of middlings instead of flour, a better quantity of flour is produced from these middlings both in color and strength than that which is made from the stones' product.
Differential speed in rolls is not only better in making middlings, but in grinding bran as well. This has been proved by several experiments.
There is no doubt but that there is less care bestowed on the hanging and care of shafting than upon any other means used in applying power to manufacturing purposes. If the steam engine or the water wheel is in good order, and performing their work properly, and the machines driven by them are also in good order, there is seldom a thought bestowed upon the media between the actuating power and its ultimate development, except the necessary attention which must be paid to the belting, and oiling of the machinery.
Often, when the result of the power is not satisfactory, it is not the driving power that is at fault, but the result may be found in the shafting, or other intermediate transferers of the power. Generally, in such a case, the belts are examined and their condition assumed for the imperfect transmission of the power from the prime mover.
The condition of the belts is a very important point in all manufacturing, but more particularly in mills where a steadiness of motion is a desideratum, and attention to them will save many dollars in the course of a year; but there are other as important elements which are not always taken into consideration, and the principal one is the condition of the shafting. A line of shafting running perfectly true, without jumping or jerking, turning smoothly and noiselessly, is a delight to the mechanical eye; and the first thing always examined by a thorough millwright when he enters a mill, is the shafting.
Perhaps there is nothing will strike a person who has been out of the milling business for some time so much as the change in the system of bolting. This is caused by the numerous separations, and it is in this the whole secret of gradual reduction lies.
PHOTOGRAPHS FOR STUDYING THE MOVEMENTS OF MEN AND ANIMALS.
By M. Marey.[2]
When a series of photographs representing the successive attitudes of an animal is taken on the same plate, it is naturally desirable to multiply these images, for the purpose of getting the greatest possible number of phases of the movement. But when the animals to be reproduced do not move rapidly, the number of images is limited by their superposition and the resulting confusion. Thus, a man running at a moderate pace may be photographed ten times in a second, without the impressions on the plate being confused. If, at times, one leg is depicted on a part already bearing the trace of another leg, the superposition does not alter the image; the whites become only more intense in those portions of the plates receiving an impression twice over, but the contours of both limbs are still to be distinguished. In the case, however, of a man walking slowly, these superpositions are so numerous as to render the reproduction very confused.
It is to remedy this defect that I have had recourse to partial photography; that is to say, I have suppressed certain parts of the image, that the rest may be more easily understood.
In the method which I employ, only white and light objects affect the sensitive plate; it suffices, therefore, to clothe that portion of the body to be suppressed in black. If a man dressed in a parti-colored costume of black and white walk over the track, by turning the white parts of his apparel toward the camera—the right side, for instance—he will be reproduced as if he only possessed the right half of his body. These images permit the various successive phases of movement to be accurately followed, the rotation of the foot and leg when both on the ground and lifted up, and the oscillation of the limb at the hip joint while moving along in a continuous manner.
These partial photographs are also useful in the analysis of rapid movements, because they allow of the number of attitudes represented being multiplied. At the same time, as a man's leg is rather large, its reproduction cannot be multiplied very often, owing to confusion by superposition. I have therefore sought to diminish the size of the images, so as to an admit of repetition at very short intervals. The method consists in attiring a walker in a black costume having narrow bands of bright metal applied down the length of the leg, thigh, and arm, following exactly the direction of the bones of the limbs. This plan permits the number of images formerly produced to be increased at least tenfold; thus, instead of ten photographs per second, one hundred may be taken. To do this it is not necessary to change the speed of rotation of the disk, but instead of piercing it with one aperture, ten holes are made equally disposed around the circumference.[3]
The figure here shown is from one of the negatives projected on the screen from the lantern. The dotted lines have been filled in to form direct lines. The figure shows the successive phases of one step in running. Only the left leg is represented; the lines correspond to the thigh, leg, and foot; the dots to the joints at the ankle, knee, and hip.
This diagram shows pretty clearly the alterations of flexion and extension of the leg on the thigh, the undulating trajectories of the foot, knee, and hip, and yet the number of images does not exceed sixty in a second. A revolving shutter pierced with more holes would give more perfectly the angular displacements of the leg on the thigh, and the positions of the three joints. The finer the dotted lines expressing the direction of the limbs, the more the images may be multiplied; but in the present case, sixty times in a second more than suffice to show the displacements of the limbs when running.
In this photographic analysis the two factors of movements—time and space—cannot be both estimated perfectly; knowledge of the positions the body has occupied in space requires that one should possess complete and distinct images; in order to obtain such images, a sufficiently long space of time must elapse between the two successive photographs. If, on the contrary, it is desirable to estimate time more perfectly, the frequency of recurrence of the image must be greatly increased. To bring these two exigencies as closely together as possible, lines and points must be chosen for the partial photographs which best show the successive attitudes of the body.
It is curious to see that this expression of successive attitudes of the trunk and limbs, by means of a series of lines expressing the direction of the bones, has been precisely adopted by the ancient authors as being the most explicit and capable of making the phases of a movement understood. Thus, Vincent and Goiffon, in their remarkable work on the horse, have tried to represent by lines at different angles the displacements of the bones of limbs while taking a step.
It is not necessary to expatiate on the superiority photography has over actual observation for this purpose, giving the true positions of the limbs, while the eye is incapable of taking in such rapid actions in such short spaces of time.
At the commencement of this century the brothers Weber had recourse to the same mode of representation to explain the successive actions produced in the walk of a man. It was by reducing the walker to the figure of a skeleton that these eminent observers succeeded in presenting, without confusion, a number of images expressing different attitudes.
The method of constructing the bright metal bands which in the photograph explain the position of the joints, requires special mention. As the length of exposure is very short, a substance having great brilliancy must be employed. The strips of metal are not equally luminous down their entire length, because they do not reflect the solar rays at the same angle; they present lines of unequal intensity on the negatives. I have obtained the best results with small strips of black wood with nails having hemispherical bright metal heads driven in at regular intervals. Each little rounded surface reflected the image of the sun very brilliantly. In the photograph these lines of nails are reproduced as dotted lines. At the ankle, knee, and hip joints, nails of larger dimensions were inserted, showing these centers of movement by a much larger dot.
Partial photographs obtained by this method allow of the different acts of locomotion being analyzed, as well as the movements of walking, running, or jumping.