Show PICTURES ON THE AIR Novel Picture Displaying DeviceS Device-S Which Can Be Made By Boys e n amusing device called the aero I scope has been exhIbited In London by I which a picture can be produced apparently I ap-parently on the air It is so simple that boys who havE magic lanterns might easily adopt the principle in giving cx hibitions for home amusement for raising funds for their clubs etc A smooth lath a couple of spools some strips of wood a wheel and a belt practically comprise the materials Secure Se-cure a patent thread pool to the end of a rod abcut four feet long and three eirhiths of an Inch in thIckness eeil lustrati n By means of a number of solid braces supporting it this stick should be made to stand uprIght from the floor or platform spool upward The braces can be nailed to the upright and the lower ends fastened to heavier material so that the spool is held firmly firm-ly In the air A small sized spool may now be forced or glued on the end of n piece of wood about the size and shape of a pencil so that it holds perfectly per-fectly tight The free end of this round I stick should fit smoothly through the larger spool HaYing marked the center i cen-ter of the lath bore a hole slightly smaller than the pencilshaped sUck I anti drive the lath on the end of the stick projecting through the larger I spool using plenty of glue to keep It from becoming loose I The remainder of the work lies In I supplying power to revolve the lath rapidly This may be accomplished by means of a wheel with a wide rim with a handle attached A tireless bicycle wheel will serve the purpose Attach It to a strong upright resting on the floor so that with an improvised crank handle attached the wheel may be turned with steadiness The wheel beset lug be-set in direct line with the smaller spool a narrow band or belting can be stretched tightly around both the smaller spool and the rim of the wheel and the ends sewn together By turning turn-ing the handle the lath may now be revolved at a great speed The room being darkened and the lantern set up an focused upon the center of the lath instead ota screen see A A all that viII be seen of a picture produced wIll be a part which falls upon the narrow strip of wood all the rest of the Image going intpthe air about the lath since there wIll be nothing noth-ing to reflect it back to our eyes But let a boy revolve the lath by means of I = < A rn f f itt 0 Iff f I Ii I I kil U j I I PICTUBEIlLAXfl5G CHINE i I his wheel crank till it makes say 300 1 I revolutions a minute and instantly the I spectators see the picture before them quite as distinctly as if on ii screen though It seems like a ghost picture for not only can the picture be seen apparently on the air but whatever may come In the line of the vIsion just back of it WeIrd effects are thus produced pro-duced by some one standing behind or placing objects In position as they can be seen through the picture almost as vividly as the bones of ones hand through the tiesh by the Roentgen rays As will be understood each position of the lath as it turns gIves the retina I a section of the picture and all these sections are seen within so short a time I that the eye retains them all and blends them Into the complete Image The moving lath is not seen during its rapid rotation all that Is noticeable beIng be-Ing a slight haziness in the all It Is only necessary to gradually reduce re-duce the velocity of the turning lath 10 arrive at a point where the Image Is no longer visible But the point at which the all picture of the aeroscope ceases to be visible is not the same for all eyes for people with great persistence persist-ence of vision continue to see it longer than others with small persistence it being visible to some when revolvIng but 60 tImes a minute By noting the number of revolutiOns per minl1te made by the lath when the picture disappears disap-pears one may thus compare his vIsual ability with that of another Amusing ghost effects can be pb tamed by the apparatus for theatrIcal purposes nictures even havIng been a success with the light turned up full The originator of the aeroscopealso believes be-lieves it will be of a great value in testing the eyes and in examining men for the signal service r |