fossil_digger Report This Comment Date: September 04, 2012 01:04AM
one of the many advanced technological skills achieved by ancient Bharatiya
Engineers.
No workshop today, anywhere in the world, knows how to do this and indeed the
casting of seamless metal spheres is regarded as technically impossible. Before
they were rediscovered in the 1980s, it was believed by modern metallurgists to
be technically impossible to produce metal g
lobes without any seams, even with modern technology.
Seamlessly cast globes continued to be made in Lahore up to the mid 19th
century. In 1842 Lala Balhumal Lahuri, a Hindu maker of precision instruments
made such a globe for his Sikh patron.
The hollow metal globe was an outstanding technical 'miracle', it being cast
seamlessly in one piece and produced by a workshop of precision instrument
makers, shocked the world's leading metallurgical experts.
No one imagined that there might be anything extraordinary about the
construction of some of these globes with their origins in classical antiquity.
The very idea that they could be cast in one piece with no seam was dismissed,
as being an impossible feat.
[Note: It's said to be from circa 1630AD inscribed in Sanskrit and Arabic both.
It is also possible that this technological wonder is far ancient and Arabic
words are just a later edition. One can observe that glyphs inscribed are
typical to Bharat.
BlahX3 Report This Comment Date: September 04, 2012 01:07PM
[
en.wikipedia.org]
Seamless celestial globe
In the 1980s, Emilie Savage-Smith discovered several celestial globes without
any seams in Lahore and Kashmir. Hollow objects are typically cast in two
halves, and Savage-Smith indicates that the casting of a seamless sphere is
considered impossible, though techniques such as Rotational molding have been
used since at least the '60s to produce similarly seamless spheres. The earliest
seamless globe was invented in Kashmir by the Muslim astronomer and metallurgist
Ali Kashmiri ibn Luqman in 1589-90 (AH 998) during Akbar the Great's reign;
another was produced in 1659-60 (1070 AH) by Muhammad Salih Tahtawi with Arabic
and Sanskrit inscriptions; and the last was produced in Lahore by a Hindu
astronomer and metallurgist Lala Balhumal Lahuri in 1842 during Jagatjit Singh
Bahadur's reign. 21 such globes were produced, and these remain the only
examples of seamless metal globes. These Mughal metallurgists used the method of
lost-wax casting in order to produce these globes.