About this time he went with the fleet to the Gulf of Saint Lawrence, and took part in the war then raging between the British and French in Canada. Winter in that region is long and bitterly cold. The gulfs and rivers there are at that season covered with thick ice; ships cannot move about, and war cannot be carried on. Thus the fleet was for a long period inactive. Cook took advantage of this leisure time to study mathematics and astronomy, and, although he little thought it, was thus fitting himself for the great work of discovery which he afterwards undertook with signal success. In this expedition to Canada Cook distinguished himself greatly-- especially in his surveys of the Gulf of Saint Lawrence, and in piloting the fleet safely through the dangerous shoals and rocks of that inland sea. So careful and correct was he in all that he did, that men in power and in high places began to take special notice of him; and, finally, when, in the year 1767, an expedition of importance was about to be sent to the southern seas for scientific purposes, Cook was chosen to command it. This was indeed a high honour, for the success of that expedition depended on the man who should be placed at its head. In order to mark the importance of the command, and at the same time invest the commander with proper authority, Cook was promoted to the rank of lieutenant in the Royal Navy. He had long been a gentleman in heart and conduct; he was now raised to the social position of one by the King's commission. From this point in his career Cook's history as a great navigator and discoverer began. We shall now follow him more closely in his brilliant course over the world of waters. He was about forty years of age at this time; modest and unassuming in manners and appearance; upwards of six feet high, and good-looking, with quick piercing eyes and brown hair, which latter he wore, according to the fashion of the time, tied behind in a pig-tail. It was not until the end of his first voyage that he was promoted to the rank of captain. CHAPTER TWO. SHOWS WHAT MEN WILL DO AND DARE IN THE CAUSE OF SCIENCE. Men who study the stars tell us strange and wonderful things--things that the unlearned find it hard to understand, and harder still to believe, yet things that we are now as sure of as we are of the fact that two and two make four! There was a time when men said that the sun moved round the earth; and very natural it was in men to say so, for, to the eye of sense, it looks as if this were really the case. But those who study the stars have found out that the earth moves round the sun--a discovery which has been of the greatest importance to mankind--though the importance thereof cannot be fully understood except by scientific men.