TRACES OF LOST WORKS 
25 
) 'problems on the 
le many elegant 
e object of which 
that is, the point 
from it, the body 
calls the assump- 
t, if a body hangs 
the body and the 
ine. Pappus has 
f support, adding 
he intersection of 
points of support» 
Y is in equilibrium 
nstic of the centre 
dng that this is 
y of the centre of 
deli are found in 
jtl5)v) and Heron’s 
itions which must 
centre of gravity 
ie longer segment 
o says that ‘ it is 
of gravity of any 
loid of revolution) 
rtion towards the 
»ossible that there 
On Equilibriums 
lilibriums formed 
:eurpof3apu<d may 
says that Archi- 
book bearing the 
tion from a work 
of mirrors) to the 
: larger and still 
rus, too, mentions 
is ; p. 548. 24, Heib. 
iting Bodies, ii. 2, 
that Archimedes proved the phenomenon of refraction ‘ by 
means of the ring placed in the vessel (of water) ’d A scholiast 
to the Pseudo-Euclid’s Catoptrica quotes a proof, which he 
attributes to Archimedes, of the equality of the angles of 
incidence and of reflection in a mirror. 
The text of Archimedes. 
Heron, Pappus and Theon all cite works of Archimedes 
which no longer survive, a fact which shows that such works 
were still extant at Alexandria as late as the third and fourth 
centuries A.d. But it is evident that attention came to be 
concentrated on two works only, the Measurement of a Circle 
and On the Sphere and Cylinder. Eutocius (ft. about a.d. 500) 
only wrote commentaries on these works and on the Plane 
Equilibriums, and he does not seem even to have been 
acquainted with the Quadrature of the Parabola or the work 
On Spirals, although these have survived. Isidorus of Miletus 
revised the commentaries of Eutocius on the Measurement 
of a Circle and the two Books On the Sphere and Cylinder, 
and it would seem to have been in the school of Isidorus 
that these treatises were turned from their original Doric 
into the ordinary language, witli alterations designed to make 
them more intelligible to elementary pupils. But neither in 
Isidorus’s time nor earlier was there any collected edition 
of Archimedes’s works, so that those which were Jess read 
tended to disappear. 
In the ninth century Leon, who restored the University 
of Constantinople, collected together all the works that he 
could find at Constantinople, and had the manuscript written 
(the archetype, Heiberg’s A) which, through its derivatives, 
was, up to the discovery of the Constantinople manuscript (C) 
containing The Method, the only source for the Greek text. 
Leon’s manuscript came, in the twelfth century, to the 
Norman Court at Palermo, and thence passed to the House 
of Hohenstaufen. Then, with all the library of Manfred, it 
was given to the Pope by Charles of Anjou after the battle 
of Benevento in 1266. It was in the Papal Library in the 
years 1269 and 1311, but, some time after 1368, passed into 
1 Olympiodorus on Arist. Meteorologica, ii, p. 94, Ideler; p. 211. 18, 
Busse.