LYMAN RIFLE AND SHOT GUN SIGHTS.
The optical principle involved in the Lyman rear sight is new in its application. When aiming it has the appearance of a ring, which shows the front sight and the object aimed at, without intercepting any part of the view. Figure I gives an ap proximate idea of how the sight appears when aiming. It will be noticed that the top of rifle barrel and front sight are seen as distinctly as if no rear sight was used. Figure 2 shows how the common open sight appears when aiming. The most important part of the view is shut out, besides the great difficulty of quickly getting the front sight in the notch of the rear sight. The aperture of the sight, being very near the eyes, is greatly magnified as compared with the notch in the common open sight. This feature gives many an impression that an aperture which looks so large cannot allow of an accurate aim; whereas, the larger the aperture looks, the more accurate the aim. The aperture could be made consider ably larger and still be accurate. Many prefer the large aperture reamed out to be 5-32 inch in diameter for wing shooting. The center of this large aperture has a degree of light the same as the light wbich is present outside of the sight. This light slightly, but gradually, diminishes as the rim of the sight is approached.
This center of stronger light partly explains the fact that the eye takes care of itself when no attention is paid to the sight, and why it naturally finds the center 1 of the aperture. With this sight there is no difficulty in using both eyes, which is always a help in shooting when one has acquired the habit. When both eyes are used the right eye does the aiming, while the left eye sees everything except the rear sight. The distance from the Lyman sight to the front sight is nearly twice as great as from the ordinary open sight to the front sight, which, in itself, doubles the accuracy. The great feature of this sight is that the eye is guided without any change of focus or effort to see more titan is seen when shooting without a rear sight. This is accomplished by a slight, but sufficient . interference of the vision of the aiming eye by the rim of the sight. The reason that the view is not obscured in any direction is that the pupil of the eye is about 1 the same diameter, in ordinary lights, as the rim of the sight is wide, and the eye sees nearly around it. With ordinary sights the eye has to observe or look at three things—the rear sight, the front sight, and the object; and, in aiming it changes its focus at least once. The eye can sec only one of these objects dis
tinctly at a time, but as it has the power of accommodation, i. e., changes its focus by flattening- or thickening- its lens at will, it first observes the relation of the front sight tt hit the rear sight. Then it must look ahead, changing this focus to observe the front sig,lit and the object, and when in this last position the front sight and the rear sight are seen together more or less indistinctly ag,ainst the object which then has the eye focus. Old eyes lose the power of accommodation and cannot change the focus of the lens, which has become hardened and flat tened. They then have accurate far sight only. Such eyes cannot use the ordi nary sights at all. The following are some of the advantages of this sight over other rear sights; 1. With this sight almost instantaneous aim can be taken, for the object is sighted as quickly as if only the front sig,ht were used. 2. This sight cannot shut out the view of the front sight, nor the object to be aimed at; while, with any other rear sight, the chief difficulty in aiming, is to bring- the sig-hts and object quickly into line without interfering with the view of the front sight or the object. 3. This sight can be used when the light becomes too dim to use any other rear sight, hence its g-reat value in the woods or late in the day. 4. Old eyes that can no longer use the crotch sig,hts can use this sight and shoot better than they- ever could with the common sight. 5. With this sight it is a hundred fold easier to shoot moving objects, running or flying, and both the ey-es can be used as well as one eye; it is also far more accurate than any other open sig-ht, and, in most respects, is better for target shooting than the peep sight. 6. Any kind of front sight can be used with this, and it is so simple and strong that there is no danger of it being- injured. 7. This sight is indispensable for a hunting rifle, and makes it possible to bring to bag much g,ame that is Oil the wing 8. Breaking glass balls from the trap is made easy; no "guesswork" about it when this sight is used. 9. It can be put on any rifle in the same way that a peep sight is attached. to. It can be adjusted for shooting any, distance up to 1,000 yards.