The longitude trail

LONGITUDE - The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time: Dava Sobel; Received from Ajay Parmer and Co., Post Box No. 7238, First Floor, Arun House, 2/25, Ansari Road, New Delhi-110002. œ.3.

THE INVITING title of this book would suggest that it is about how longitudes running between the North and the South poles of the Earth were visualised and drawn. Actually it tells us a lot more about the inventors of clocks which the intrepid seafarers of the ancient times and the Middle Ages needed badly to free themselves from the timelessness of the void in which they found themselves in the midsea.

The longitudes remained a guide only to the extent that while the mariners sailed away, they ``gained'' four minutes while sailing from one longitude to the next on the west and ``lost'' by as many minutes on the east. What, therefore, mattered most for them was the measuring instrument which would mark out the time for them wherever they were.

The book tells us more about horology and the English clockmaker, John Harrison (1693-1776 A.D.), who had to struggle very hard against those who were not only mean but also powerful to win the recognition and the rich rewards he fully deserved for his inventions progressing in accuracy from H1 to H4.Though a good part of her book is devoted to clock-making and the inventors, Ms. Dava Sobel tells us at the beginning how the sailors of the ancient times and right up to the 18th century depended heavily on the positions of the moon and the stars to arrive at the correct longitudes of their locations and also the solar and lunar eclipses.

Galileo's exploration of space from his earthbound existence for placing the longitudes correctly in 1610 A.D. took him to the huge planet, Jupiter, and its moons and their eclipses. And he could do this with just the telescopes he could rig up in his time. Sir Isaac Newton's theory of gravitation was another giant step forward towards the marking of longitudes. Among the discoveries to which the longitude trail had led was the moon's irregular elliptical orbit around the Earth.

The book, which is about inventors like John Harrison and the placing of longitudes, retells the story of the infamous Captain Bligh of HMS Bountywhich was celebrated in celluloid by ``The Mutiny on the Bounty'' and Captain Cook's voyage to the South Pole. Charles Darwin's Beaglevery much belongs to the same era when longitudes began criss-crossing the Earth with latitudes the demands for the marking of which were far less strenuous. Ms. Sobel has written a very informative and a readable book.

CVG

Send this article to Friends by E-Mail

Section  : Features
Next     : Relentless quest