Portal logo
after completing his education, he engaged himself in independent scientific research beginning at least from the year 380/990 when he made an
astronomical observation. He continued his work uninterrupted for the
next five years until 385/995 when civil war broke out and Beruni left
the country. He remained out of Khwarazm for the next fourteen years
(385 — 399) except for a temporary visit to Kath in 387/997 to observe a
lunar eclipse. He finally returned to his country some time before or
early in 399/1008, this time to Jurjaniyah the capital of Abu al-Hasan
Ali, the ruling Prince of the new Mamunid Dynasty, who had specially
invited him.
It was on the basis of his specialized knowledge based on his experimentally verified conclusions during this period that he came to be recognized as an authority on gemstones and was officially assigned the
responsibility to oversee the annual despatch of presents, which would
include precious stones of rare quality, to the Ghaznavid Sultan Mahmud
(cf. K. al-JamaUir, present ed., p. 47) by his brother-in-law Prince Abu
al "Abbas Mamun of Khwarazm 399—407 A.H. Thus, mainly it was
during the period of about 9 years (399—407 A.H.) prior to his arrival in
Ghaznah in 408/1017, that Beruni had devised and perfected his apparatus and instruments, conducted his experiments and determined relative weights and volumes as well as specific gravity of a number of
metals and gemstones with precision.
On the hydrostatic method of finding specific gravity, Beruni observed thus: "Scientific men determine by means of water the measure
ol these differences in weights. They prepare a vessel filled with water in
which they introduce 100 mithqals of each of the metals; the quantity of
water thrown out by each gives the difference in volume and weight. —
that one which displaces the largest bulk of water has consequently the
largest volume but the least density, and that one which displaces the
least water is the heaviest." The special flask for holding water which he
designed, was rightly called by Khazini after the name of Abu al-Rayhan
Al-Beruni as "The Conical Instrument of Abu al-Rayhan''. While experimenting with it, Beruni detected the capillary action which caused the
water to rise in the tnizah, with drops thereof remaining suspended in its
curveture. Also, Beruni visualised the solution that if the mizab were
given a circular flexture, made shorter than a semi circle and pierced with
holes, the water will flow down through it smoothly without any of the
droplets remaining suspended. He also understood it that the length and
the diameter of the flask's neck affected the experiment and noted that
"he could have made it narrower than the little finger" but for the difficulty of inserting through it down into the vessel and again taking out of
it the somewhat larger pieces of metals/minerals. After gaining such insights, he modelled to near perfection what historically became "Beruni's
xvu