464 THE POPULAR SCIENCE MONTHLY 
one another, or stand farther distant asunder.” He says perpendicular 
means level, or a plumb line. Webster, in his 1828 dictionary, says an 
angle is the space comprised between two straight lines that meet in a 
point; but he adds also that an angle is the quantity by which two lines 
diverge from each other. 
Though the term per cent. in arithmetic is a simple one, the defini- 
tion of it in practically all the arithmetics and dictionaries wraps it in 
a fog. A very considerable part of the trouble pupils in school have 
with percentage is due to obscurity in this definition. This seems like 
a bold statement to make, but the reader can judge for himself whether 
it is probably true when he hears the case stated. In simple English 
the word per cent. means hundredths. Thus, six per cent. means six 
hundredths. Instead of giving this definition the books say per cent. 
means “by the hundred” or “in the hundred.” If this is so then 
6 per cent. means six by the hundred, which means nothing. Dr. John- 
son, who was no mathematician, said that per cent. meant “in the 
hundred,” and all the lexicographers seem to have followed his lead, 
merely varying his preposition. Webster (1828) says: “In commerce 
per cent. denotes a certain rate by the hundred. ‘Ten per cent. means 
ten in the hundred.” Webster’s International states that per cent. 
means “ by the hundred,” “ in the hundred.” Of course there is a way 
of giving concrete meaning to these words. Thus 2 per cent. in com- 
mission can mean that the agent gets $2 in every $100 worth of goods 
he sells, or he gets $2 by every $100 worth of goods he buys. One sees 
the obscurity in these phrases, however, very clearly, by using another 
denominator. Thus, what does 2 by the 8 mean? 
In the preface to his dictionary Dr. Johnson says: “ Every other 
author may aspire to praise; the lexicographer can only hope to escape 
reproach, and even this negative recompense has been yet granted to a 
very few.” Evidently from this lexicographers had a harder time in 
those early days than they have now; for nowadays it would seem as 
though the dictionaries were to be regarded as sacred writings, to 
criticize which would be sacrilege. Had the dictionary makers been 
criticized more, most likely they would have improved the quality of 
their work. The writer has heard it said that the dictionaries are as 
weak in defining other similar technical terms as in their definitions of 
mathematical terms, and that they are far behind the progressive 
cyclopedia makers in the quality of the matter they print. It would 
seem judging from the preceding mathematical definitions as though 
the greatest opening for a progressive publisher would lie along the 
way of bringing out a new unabridged dictionary adapted for the use 
of the mass of twentieth century Americans. 
