96 
THE YOUNG SCIENTIST. 
enables object-glasses of higher power to 
be made than would otherwise be practi- 
cable. For example, the radius of the 
front lens of a i-50th is l-120th of an inch, 
and the diameter is l-70th. The difficulty, 
if not impossibility, of constructing a 
triple of such almost invisible atoms of 
glass may be imagined. 
Science in Common-Place Things. 
UNDEE the somewhat taking title, 
"Physics Without Apparatus," our 
French cotemporary. La Nature, has pub- 
lished a series of articles which have been 
extensively copied and quoted. Unfor- 
tunately the title is a misleading one, for 
the author constantly uses aq^paratus. 
his experiments not being in any sense 
illustrations of the principles which they 
are said to render clear. The engravings, 
however, are very fine as works of art, 
and we have therefore procured several of 
them, which we shall present to our rea- 
ders with original and accurate explana- 
tions, and more minute details in regard 
to the best methods of performing the ex- 
periments. 
Of the value and importance of experi- 
mental illustrations of the laws of science, 
no teacher of experience has any doubt. 
One of the great difficulties in the way of 
such experiments, however, is the expense 
of the necessary pieces of apparatus, and 
the difficulty of using them. Several 
writers have endeavored to suggest means 
LIFTING A DECANTEB BY A STKAW. 
and in some cases he employs apparatus 
which can be obtained only from dealers 
in philosophical instruments. And it is 
still more unfortunate that the explana- 
tions and directions are in all cases 
meagre, and in many erroneous, some of 
for overcoming this obstacle— the most 
noteworthy attempt being that of the late 
Dr. Paris, in his "Philosophy in Sport 
made Science in Earnest." In a recent 
article upon this subject, the English 
journal, Nature, thus attempts to impress 
