88 
THE YOUNG SCIENTIST. 
former number ; pumice it carefully, so as 
to leave no scratches, and whiten it lightly. 
When quite dry, rule lightly with a fine 
pencil, some " guide " lines, from the top 
to the bottom about quarter of an inch 
apart. 
Place the block on your sand bag cush- 
ion described in March number, and all 
your apparatus adjusted as there di- 
rected. Hold the block with your left 
hand firmly to prevent it slipping, but so 
that you can readily move and turn the ' 
and cut slowly, and not too deeply, a line 
straight as possible across the block. It 
would be well to cut this first line, just 
below the pencil " guide line," at the top 
of your block. Keep the same pressure 
of tool into the wood throughout the en- 
tire length of line. Having determined 
what width of line, or *'face" you will 
leave, when you commence the second 
line, place the tool at the required distance 
below your first cut, and cutting into the 
1 wood the same depth as before, guide the 
Fig. 13. 
block as required while engraving. The 
left hand performs a very essential ser- 
vice in making engravings. 
Select a tool of medium grade for the 
first lesson, holding the tool and adjust- 
ing the block as described; commence 
near the upper edge, and just on the right 
side ; guide the tool with the forefinger. 
tool slowly across the block, endeavoring 
to leave the line as wide throughout its 
entire length as at its beginning. 
The line that is between your two cuts 
is the first line of your tint, for the lines 
that are left are the lines that receive the 
ink in printing, and the straight cuts ap- 
pear white. The quality of plain tint de- 
