00441nam a2200169Ia 450000500170000000800410001708200150005810000110007324500240008426000440010830000150015265000230016765000160019065000170020665000170022365000310024020260525173336.0260525b        |||||||| |||| 00| 0 eng d  a666.156 J7  aTwymau 0aPrism & Lens making  c1957b Hilger ot watls l.t.daWashinton  avii, 235p.  aPlastic Technology  aGlass Prism  aLens Making   aOptical Work  aSurface Treatment Of Glass