A UNIQUE COLLECTION OF ARITHMETICS 231 
cussion of arithmetic. Finger reckoning and a number game called 
Rithmomachia are other related subjects which received elaborate treat- 
ment. The first modern encyclopedia to appear in print is the 
“Epitome of all Philosophy” by the Carthusian monk Gregorius Reisch, 
the publication appearing in Strassburg in 1503. “ Pythagoras” and 
“ Boethius ” adorn the first page of the part devoted to arithmetic. 
It would appear that scientists have, in the course of centuries, 
grown more modest in their published claims. Borghi’s “ Noble work 
of arithmetic treating all those things which are requisite for mer- 
chants” sounds like a boast. More seductive are “The Ground of 
Artes,” “The Castle of Knowledge,” “The Pathway of Knowledge” 
and “The Whetstone of Witte,’ mathematical works by Robert 
Recorde, the royal physician to Edward VI. and Queen Mary. Recorde 
was the first to use the present equality sign, stating that no two things 
can be more equal than two such lines. His were the most influential 
English mathematical publications of the sixteenth century. Equally 
enticing as’ the titles of Recorde was Humphrey Baker’s “The Well 
spring of Sciences, Which teacheth the perfect work and practise of 
Arithmetick, both in whole Numbers and Fractions” (London, 1562). 
The most fitting name with which to terminate a discussion of the 
printed arithmetics of the sixteenth century is that of Adam Riese. 
So widely were his books used and so deep the impression which they 
made that even to-day, nearly four centuries after he wrote, the expres- 
sion to reckon “nach Adam Riese” is common in Germany. Riese’s 
works quite supplanted the numerous editions of the Rechenbuch by the 
versatile Jakob Kobel, who was Reichenmeister, printer, engraver, wood- 
carver, public official, as well as a successful text-book writer. Kobel’s 
“ Rechenbuch” of 1514 bears silent but eloquent testimony to the 
tremendous inertia that must be overcome by any new system that 
revolutionizes the common processes of thought. Kobel’s arithmetic, 
four hundred years after the Hindu-Arabic numerals had been explained 
in Europe, is wholly in Roman numerals, even to the fractions. Riese’s 
work made the publication of any other arithmetic in Roman numerals 
impossible. 
Part II. of the “ Rara Arithmetica” treats of the rich collection of 
mathematical manuscripts in the Plimpton library. The oldest of these 
is a beautifully written Latin Euclid (about a.p. 1260). This manu- 
script appears to be the copy given by the translator Campanus to 
Jacques Pantaleon when he was Patriarch of Jerusalem. Campanus 
was chaplain to Pantaleon both in Jerusalem and later when that 
churchman became Pope Urban IV. 
An arithmetic written about 1339 by Paolo Dagomari, also known 
as Paul of the Abacus, furnishes the clue to the derivation of our per 
cent. symbol. The sign is derived from the abbreviation c° for cento 
