Il4 Answers to Queries. 
windows of which must be coated with wax, and the vessels used 
to contain the acid must be made of lead. Monograms and 
similar designs are printed in a kind of thick ink, on transfer 
paper, the lines of the monogram being left uncovered by the 
ink. The pattern is then transferred to the glass, the ink pro- 
tecting the portions covered from the acid in the subsequent 
processes. As, however, the monogram only covers a small 
portion of, say, a wine-glass, or decanter, the rest is coated with 
wax. The bath of hydrofluoric acid is then used as before. 
The pretty zig-zag patterns which so frequently adorn many 
wine-glasses are scratched on the wax by means of several inge- 
nious machines. One of the simplest patterns, which is a sort 
of ‘“trochoidal curve,” is produced by the tracing point rapidly 
revolving in a circle, while the glass slowly turns round on its axis. 
Another well-known pattern is traced out by a rather complicated 
mechanism, in which, by means of wheels having cogs along half 
their circumference, the tracing points are made to move up and 
down, and the glass to turn round, alternately, in a series of jerks. 
Although most of the patterns on glass are etched in this way, 
they lack the sharpness of definition required for the very best 
engravings. These latter are therefore carefully ground by hand, 
very small rapidly-rotating wheels covered with fine rotten-stone 
powder being used to cut out the pattern on the glass. A large 
number of wheels of different shapes and sizes must be used for 
the various details of a complicated design, such as a bunch of 
flowers and fruit, and this method is only resorted to in the case 
of the most expensive dessert sets, as it involves a considerable 
amount of skilled workmanship. 
With regard to the embossed patterns, so common on butter- 
dishes and similar articles, these, as well as the lenses used in 
lighthouses, are formed by pressing the molten glass into moulds 
of the desired form. ‘The flutings and ribbings on decanters, and 
the familiar lozenge or diamond patterns on cruets, are carved on 
the glass by means of grindstones, whose edges are rounded, 
angular, or flat, as the case may be. In the preliminary grinding, 
rotten stone and water are used, but for the final polish the finest 
putty powder is required. 
We are indebted to Messrs. Molyneux and Webb for their 
kindness in conducting us over their glass-works at Manchester, 
during the visit of the British Association, and in explaining the 
various processes which I have here attempted roughly to describe, 
as well as for a large amount of other information respecting the 
manufacture of glass. Gs Ee Be 
350.—Penicillium Glaucum is familiar to everyone from its 
forming sage-green crusts upon bread, jam, boots, etc. Prepare 
some Pasteur’s fluid, and leave exposed to the air in saucers in a 
a 
