Up: Patent Index

583,594 · Ewen · "Prismatic Light" · Page 2 Home  > Prism Glass  > Patent Index  > Page 2

583,594: 2 of 3

and thus, as varying conditions may require, to superimpose the other window-light, and thus change the character of distribution. These results of course will depend upon the character of the prisms used. Moreover, on some occasions and with windows situated in a certain manner it would be desirable to use but one set of prisms on a very bright day, while on a dark or cloudy day the increased illuminating effect due to the use of both sets of prisms might be desired.     I have shown in the prisms one and the same angles, but of course I might use one angle in one glass and another angle in another glass-- that is to say, the first sheet of glass section might be a certain angle, while the next sheet would be a different angle, and any desired angle can be used on either, and each light can be made up of several sections or not, as the case may be.     The line E represents light coming from about fifty-one degrees from the horizontal, and E' represents the direction which it takes in the body of the outside plate.     E² represents the direction which it takes in the second body or plate of glass, and E³ the direction which it is desired to give such light in order that it may have the useful effect of illuminating the room. If the plate or inner body of glass were absent, the light in question would take the direction E4 and be practically useless. On the other hand, light coming from the direction F is refracted so as to take the direction F' in the outer plate, whence it passes in the direction F² into the room and needs no inner plates or prisms. This illustrates the fact that with certain prism-lights which are useful separately under conditions where the light is received along the direction F such prisms are wholly useless under other conditions-- as, for

example, in a case where high buildings or obstructions are located on the opposite side of the street. In such case by a duplication of the plates they coact in such way as to produce the desired result.     I claim as new and desire to secure by Letters Patent--     1. The combination of two layers of prismatic lights placed so as to receive the light successively and transmit it from one place to another.     2. The combination of two window-lights each consisting of a series of sections of prismatic glass, the two lights associated together in proximity and parallelism so that the light passes through them successively.     3. The combination of two window-lights each consisting of prismatic glass, the prisms on the two of the same size and shape, and the two lights related in close proximity and parallelism, so that the light passes through them successively.     4. The combination of two window-lights, each consisting of prismatic glass, the prisms on the two of the same size and shape and having each one face substantially perpendicular to the plane of the light and the other face inclined thereto, and the two lights related in close proximity and parallelism so that the light passes through them successively.     5. The combination of two window-lights, each consisting of prismatic glass and associated together in hinged relation so that one or both can be used to control the aperture through which the light is to be received. JOHN M. EWEN. Witnesses:     DONALD M. CARTER,     BERTHA C. SIMS.