24 THE YOUNG 
them. What is true in mechanics, is true 
of mind. Every result is produced only 
by a sufficient cause, and we never find 
that any one becomes an expert without 
long and earnest work. 
Literary men who wish to make their 
writing more pleasing than instructive, are 
very apt to pander to the feeling of pleas- 
ure which we all take in wonderful stories, 
and they have filled the history of science 
with fables in which they tell us that al- 
most all great discoveries were the result 
of accident. Thus we are told that the 
Galvanic battery owes its origin to some 
frog's legs, prepared for soup for Madam 
Galvani, and hung on an iron railing. 
The wind blew and moved the legs away 
from the metal, and then allowed them to 
fall against it again, and every time they 
touched the iron they gave a convulsive 
twitch. Galvani saw it and invented the 
galvanic battery. 
This whole story is a fable. At the time 
spoken of, Galvani had been engaged for 
years in experimenting on animal elec- 
tricity, and had often used frog's legs as 
electroscopes, but in spite of all this, he 
did not invent the battery which was de- 
vised some years after Galvani's death, by 
Volta, and should be called the Voltaic, 
and not the Galvanic battery. 
The same class of writers tell us that 
Newton was led to his famous discoveries 
by the falling of an apple as he sat in his 
garden. The most careful research fails 
to find any ground for this story. Newton 
was engaged for years in working out his 
famous discoveries ; he was not led to them 
by any accident, but by honest hard 
work. 
Another stor^^ is that told of Galileo, 
that he invented the pendulum from see- 
ing a chandelier swinging in a church. 
Pendulums had been used long before his 
day, and at the time he saw the chandelier 
he had been studying the subject for 
years, and merely used it as an illustra- 
tion of the great laws which he was en- 
deavoring to work out. 
Another story is that of Watt, who is 
said to have invented the steam engine 
from seeing the steam lift the lid of a ket- 
tle as he sat by his mother's fireside. 
Now it happens that steam engines were 
SCIENTIST. 
in extensive use in Great Britain long be- 
fore Watt was born, so that the power of 
steam was well known. Watt, however, 
made a careful study of the properties of 
steam, and experimented upon the subject 
until he was familiar with all the facts in 
the case. After this hard work and ex- 
perimenting, he was able to so improve 
the steam engine of his day that his fame 
will last as long as our modern civilization 
endures. 
The lesson to be drawn from all this is, 
that if we would succeed, we must depend 
upon good hard work and not upon luck. 
Luck rarely does much for any one, and if 
we w^ait for accidents to help us, we may 
wait in vain for ever. 
Designs for Scroll-Sawyers. 
ME. HODGSON, whose admirable arti- 
cles on scroll-sawing are now in course 
of publication in the Young Scientist, has 
prepared for us a series of seventeen designs 
covering a great variety of subjects suit- 
able for Christmas presents and ordinary 
articles of household ornament and util- 
ity. These designs w^e have had photo- 
lithographed and printed on two large 
sheets. They are full size and embrace 
over eighty different pieces. Knowing 
that this set must have a large sale, we 
have placed the price at 25 cents for the 
set, or a cent and a half for each design. 
We know of no designs equal to these 
which can be had for less than five, ten, or 
twenty cents each. 
To any boy or girl who will send us a 
new subscriber to the Young Scientist (to- 
gether with their own subscription) we 
will send a set of these designs free. The 
subscriptions may be for 1878, 1879, or 
1880. Kemember, one of the subscribers 
must be new. It will not do to send a 
renewal of the subscriptions of two old 
subscribers. 
BOOK NOTICES. 
Laboratory Teaching-: or. Progressive Exer- 
cises in Practical Chemistry. By Charles Lou- 
den Bloxam, Professor of Chemistry, in King's 
College, London, etc., etc. Fourth Edition, with 
Eighty-nine Illustrations. Philadelphia: Lind- 
say & Blakiston. 
This is a most excellent little book, clear and 
full on all those points in which the beginner re- 
