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The celestial globe
was introduced in the Indian subcontinent during the reign of Humayun. An important improvement in making celestial globes is to
be noticed in India. In other countries, the celestial globe was
made by combining two hemispherical hollow-structures together; but
in India the complete hollow sphere was cast in one piece through
the cire perdue or lost wax method, employed since the
ancient times for casting bronze images. The city of Lahore was the
most well-known centre for making celestial globes. These were used
essentially for teaching and demonstration. Their manufacture and
use continued in India till the 19th century.
Sun-dials are generally considered to be the earliest
scientific instrument invented by man to measure time. The early
Egyptians and Babylonians were its pioneers. It was further improved
by the Greeks and the Arabs. The sun-dial indicates time by
measuring the apparent passage of the sun through its daily course
in the sky. The calibration of the dial, based on the orientation of
the sun to the earth during the course of the day, enables the
determination of the correct solar time as the shadow moves around
the dial. The solar time, however, is different from the clock time
since the latter is based on the sun’s apparent movement.
Sun-dials are of different types but the most commonly used are the
directional types. There are interesting references to the making of
sundials and clepsydrae (water-clocks) in medieval India, especially
from the reign of Firoz Shah Tughluq. However, the sundials included
in the album are those inspired by the European proto-types which
developed in the Renaissance period and were further improved down
to the 19th century, before the mechanical clocks took
over.
Significantly, Patna was a well-known centre for making
sundials in the 19th century. Shad Azimabadi, in his
Tarikh-e Bihar, mentions Taj and Mangaran as two very proficient
craftsmen who made sun-dials which gained acclaim even in Europe.
Entry (7) in the present album is a sun-dial made by Mangaran.
Another sun-dial made by Mangaran is preserved at the Victoria and
Albert Museum, London.
The The The The Roznuma-o-Shabnuma (Quadrant-cum-Nocturnal)
was used for indicating time both during the day and night. It
combined the Quadrant – used for the day time – with the Nocturnal,
used for the night time. The Quadrant was known since the days of
Ptolemy, and is usually shaped like the quarter of a circular disc. |
