Seamless celestial globe

All of us are familiar with an ordinary terrestrial globe which shows the earth, with its physical and political characteristics. A celestial globe shows the night sky with stars and their constellations. In a celestial globe the positions of the stars are recorded with the use of coordinates in relation to each other. These were used primarily for solving problems in celestial astronomy. The altitude of the Sun and the right ascension and declination of the stars could be calculated with these by inputting the location of the observer on the meridian ring of the globe. These globes were used previously in analogue computer devices to record the positions of the stars and study their movements. These days, one can get an educational celestial globe from any shop that sells globes and children can get a basic grounding in the field of astronomy by studying these globes. It is a pity that such globes are not available in Kashmiri markets.

The invention of the celestial globe is generally attributed to the Chinese. About 4th century BC, the Chinese were using these devices to make astronomical calculations.  Later on, this invention of the Chinese was further developed by the Koreans.  The modern world recognizes the celestial globe invented by the Greek astronomer Eratosthenes as the first authenticated version of the instrument. Many Islamic astronomers and medieval Europeans have also contributed to the development of the celestial globe. In the 12th century, Jabir ibn Aflah (Geber) was the first to design a portable celestial sphere to measure and explain the movements of celestial objects. The credit for the invention of the seamless celestial globe goes to the Indians and that too to a Kashmiri. Considered one of the most remarkable feats in metallurgy, it was invented in Kashmir by Ali Kashmiri ibn Luqman in 998 AH  and twenty other such globes were later produced in Lahore and Kashmir during the Mughal Empire. Ali Kashmiri created many masterpieces in Kashmir  in the reign of the Mughal Emperor Akbar, and during  Akbar’s rule the craft found its way into the city of Lahore.   The largest globe was made during the reign of Mughal Emperor Shah Jahan by Muhammad Salih Tahtawi. It was being inscribed in both Arabic and Persian. The last was produced in Lahore by astronomer and metallurgist Lala Balhumal Lahuri   during Sikh ruler Jagatjit Singh Bahadur’s reign. Seamlessly cast globes continued to be made in Lahore up to the mid 19th century until the arrival of the British Empire. Before they were rediscovered in the 1980s, it was believed by modern metallurgists to be technically impossible to produce metal globes without any seams, even with modern technology. Hollow objects are typically cast in two halves. These Mughal metallurgists pioneered the method of lost-wax casting while producing these seamless globes.