Show interesting trick TO P PLAY LAY board projecting over table and covered with newspaper cannot so bo K knocked to floor take an ordinary board two or three feet long such as a br bread ead board andi andi place iton it on the table so that shout about one third of 0 its length will project over the edge unfold a newspaper and lay it on the table over the board says the mechanics any one not familiar with tho the expert ment would suppose the board could be knocked off by hitting it on the outer end it would appear to be easy todo to do but try it unless you yon are prepared to break brcak the board you proba bly will not be abia abl td to knock the anard off the reason Is that when the board la Is struck it forces the other end up and the newspaper along with it this causes a momentary vacuum to be formed under the paper and the pressure of the air above which Is about fifteen pounds to the square inch prevents the board from coming up this Is an entertain entert entertaining aln ifie trick lo 10 play at an evening party and also makess makes a simple and interesting experiment |