508 The Book of the Balance of Wisdom. [October, 
of the Balance of Wisdom according to Abu-Hatim al- 
Muzaffar Bin Ismail, of Isfazar. “ He begins by remarking 
that the balance being an instrument of precision, like astro : 
nomical instruments such as the astrolabe and the zijassa- 
faih, its whole workmanship should be carefully attended to. 
He next describes the beam, the front piece, the two 
4 cheeks ’ between which the ‘ tongue ’ moves, and the 
tongue itself.” He gives the length of the beam as 4 bazaar 
cubits (2 metres), and remarks that “ length of the beam 
influences the sensibility of the instrument;” it is con- 
structed of iron or bronze. The balance is provided with 
live bowls or pans, made of very thin plates of bronze, three 
of which have the form of hemispheres (see Fig. 4), one of 
which is spherical, and the remaining one, destined to be 
plunged into water, is finished with a conical bottom. Two 
of these bowls bore the name of the “ aerial,” and were 
permanently attached to the beam ; another pan was 
movable on the right arm of the beam ; and the bowl in- 
tended to be immersed in water was fastened underneath 
the aerial bowl of the left arm : this bowl bore the name of 
the “ aquatic,” and the spherical bowl was named the 
“ winged.” 
We cannot here enter upon a more detailed examination 
of this portion of al-Khazini’s treatise ; suffice it to say, he 
speaks of the mode of adjusting the balance and of its ap- 
plication to the examination of metals and of precious 
stones. Al-Khazini distinctly states that in taking the spe- 
cific gravity of bodies he employed “ a determined sort of 
water, similar in density to the water of the Jaihun of 
Khuwarazm,” and further that “we made all our compari- 
sons in one single corner of the earth, namely, in Jurjaniyah 
[a city] of Khuwarazm, .... and early in the autumnal 
season of the year.” The “ Jaihun ” is the modern river 
Oxus, and “ Khuwarazm ” corresponds to the modern pro- 
vince of Khiva. 
The editor, M. Khanikoff, calls special attention to the 
following passages, which he considers the most remarkable 
in the whole treatise : — 
<s When a heavy body, of whatever substance, is trans- 
ferred from a rarer to a denser air, it becomes lighter in 
weight; from a denser to a rarer air it becomes heavier.” 
— (LeCt. I., Chap, v., § 1.) 
“ Air-weight does not apparently vary, although there is 
aCtual variation, owing to difference of atmospheres. As 
regards its water-weight, a body visibly changes according 
to the difference between waters of [different] regions, wells, 
