P. HISTORY OF ' AATHEMATICAL - School of Mathematics

14 A HISTORY OF MATHEMATICAL KOTATIOKS
1764, J. A. Fad in 1775. On the other hand, D'Alembert2 in 1747
and in 1764 used the letter c for 2.718 . . . . , as did also the astrono-
mer Daniel Melandria of Upsala in 1787. The letter e for 2.718 is
found in Abbe Sauri,' in E. BBzo~t,~ in C. Kramp.6 In Italy, P. Frisi,'
NOTE ON T\VO SEW SS3InOLS.
-
nr ncs.r.\rIs I.i:lncc,
Pmfauor of 3btLmalics In IIarrard Collcge, Crmhridp, 5 1 ~ ~ .
-
T~IE symbols which are now usc? to denote thc Kcperinn bnsc
and the rntio of the circt~mference of n circle to its dinmctcr arc,
for many reasons, inconvenient ; and thc close rclntion. bcttvccn
thcse two quantities ought to be indicated in thcir notation. I
would propose the following characters, which I liavc usccl with success
in my lectures :-
to denote ratio of circumference to diameter,
(jl to denote Neperinn base.
It d l bc seen tlnt the former symbol is a modification of the
lcttcr c (circtt~~fcrc~~cc), and tll~ httcr of ,b (base).
The conncction of tllcsc qu~nntities is shown by thc ecyuatiog,
an = (- l)-Gi.
FIG.
'107.-B. Peirce's signs for 3.141 . . . . and 2.718 . . . .
in 1782, and Pietxo Ferroni,B in the same year, used C for 2.718 . . . . ,
but Paolie adopted the e. A. de Morganlo in 1842 used the epsilon e
for 2.718 . . . . and E for edz.
1 J. A. Fa, Inleiding tot de Kennisse en het gebruyk der Oneindig Kleinen (Leyden,
1775), p. 71.
2 D'Alembert in Hisla're de l'dhie, annee 1747 (Berlin, 1748), p. 228;
annQ 1764 (Berlin, 1766), p. 412.
a Daniel Melandri in Nova Acla Helvetica physico-mdhematica, Vol. I (Baael,
1787), p. 102.
4 L'AbbB Sauri, Cours de mathbmntiques, Tome I11 (Paris, 1774), p. 35.
". BBzout, Cours de mathWiq;ues, Tome I (2d ed.; Paris, 1797), p. 124.
8 C. Kramp, Elknenfs d'arithmdtique (Cologne, 1808), p. 28.
7 Paulii Frisii, Operum tomua primw (Mediolani, 1782), p. 195.
8 Pietro Ferroni, Magniludinum ezpaentialium logarithmwum et Trig*
netrim sublimk themk (Florence, 1782), p. 64.
9 Pietro Paoli, Elenenti d'dgebra, Tomo I (Ph, 1794), p. 216.
10 A. de Morgan, "On the Foundations in Algebra," Tranaactiona of the Cambridge
Philoa. Society, Vol. VII (Cambridge, 1842), p. 185.