Show EL K LETTERS AND WHITE former cn can be read at a greater greate r distance tance than the latter I 1 Is judgment of experts expert there Is a tendency on the part of 0 railroads to adopt signs with white letters ou on a i black background not 1 11 l cle ck ile I le nn n a ite 1 V l cund i aar ead ed r an bep i va fa f t a 1 r rt t 1 buc 1 I his 8 n n tl isn ironi from th tb r 0 o eye r t a i r al the t TI i i ii qc aride cride vt I 1 vl ANI ron wf V r to of 1 im yva i v a to ito the to 0 o N hether cir orB not a i in i loon apon it and when w if e light a oa 04 patti parti i la ft the rs br orn 1 i i i 1 0 it was in 1 light it follows lol iol lows therefore that hot all al artes on it the dividing edge between any black and white while area transmit tran the bensadon of light so that all white lines a nd white areas appear wider and all black lines and black areas appear narrower than they really are black letters grow thinner at the limit ot of vision and are still recognizable while at the same distance white letters grow thicker and cannot be distinguished there are circumstances when it Is necessary to use white letters but in such cases lep legibility will be improved II if they are made with a thin stroke and strongly lighted 11 cited black letters are more it if made with n heavy stroke Scie scientific ile american |