so that these projections correspond to intended to facilitate the discovery of leaks in gas mains or sensitizing with bichromate of potash. their respective depressions, at which position, if the nuts pipes. A glass tube is fixed in a very much flattened fun- To imprint the gelatine relief upon… … deposits of bitumen. Now while asphalt is highly combus- is, that the gelatine relief is more easily impressed upon thin tible there seems to be: at present no practicable method to sheets of lead than upon thick plates by hydraulic pressure. have been properly constructed, their wrench surfaces…
Internet Archive · Public domain (published before 1931). Free to use for anything.
