rious in eating and drinking, in apparel and horses. With us a want of cleanliness is equivalent to insupportable misery and misfortune. Thanks to the labors of science, the price of soap at the present time is such as to debar not even the poorest from its unrestricted use.

When Hume thought that a nation would be behind in the manufacture of cloth that had not studied astronomy, he perhaps did not mean to go the length of saying, that the study of astronomy has a real influence in making cloth cheaper, in lessening the cost of production, and in therefore increasing the number of consumers. But look at the direct influence of astronomy upon navigation. A seaman, by the guidance of principles laid down by the great minds that have directed their mathematical powers to the study of astronomy-such minds as those of Newton and La Placemeasures the moon's apparent distance from a particular star. He turns to a page in the "Nautical Almanac," and by a calculation directed principally by this table, can determine whereabout he is upon the broad ocean, although he may not have seen land for three months. Sir John Herschel, has given in his "Discourse on the Study of Natural Philosophy," an instance of the accuracy of such lunar observations, in an account of a voyage of eight thousand miles, by Captain Basil Hall, who, without a single landmark during eighty-nine days, ran his ship into the harbor of Rio as accurately, and with as little deviation, as a coachman drives his stage into an inn-yard. But navigation not only depends upon lunar distances, but upon an instrument which shall keep perfect time under every change of temperature produced by variety of climate. That instrument is a chronometer. Every one who possesses a watch, however good, must have experienced the effects of heat or cold upon its accuracy, in making it go faster or slower-perhaps a minute in a week. Now if there were not an instrument

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that would measure time so exactly that between London and New York not a minute, or large fraction of a minute, would be lost or gained, the voyage would be one of difficulty and uncertainty. A Yorkshire joiner, John Harrison,

at the beginning of the last century, found out the principle of the chronometer, which consists in the union in the balance-spring of two metals, one which contracts under increased temperature, and one which expands; and on the contrary under diminished temperature. Harrison worked for fifty years at his discovery; and he obtained a parliamentary reward of £20,000.

The English chronometers are set by what is called Greenwich time. The beautiful instruments that are constantly at work, and the laborious calculations which are daily proceeding, at the Observatory, are essentially necessary for the maintenance of a commerce that embraces the whole habitable globe.

But what has this, it may be said, to do with the price of clothing? Exactly this: part of the price arises from the

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cost of transport. If there were no "lunar distances" in the "Nautical Almanac," or chronometers, the voyage from New York to Liverpool might require three months instead of a fortnight. But go a step farther back in the influence of science upon navigation. There was a time when ships could hardly venture to leave the shore. In the days of our Anglo-Saxon ancestors, a merchant who went three times over the sea with his own craft, was entitled to rank as a thegn, or nobleman. Long after this early period of England's navigation, voyages across the Atlantic could never have been attempted. That was before the invention of the mariner's compass; but even after that invention, when astronomy was not scientifically applied to navigation, long voyages were considered in the highest degree dangerous. The crews both of Vasco de Gama, who discovered the passage to India, and of Columbus, principally consisted of criminals, who were pardoned on condition of undertaking a service of such peril. The discovery of magnetism, however, changed the whole principle of navigation, and raised seamanship to a science. If the mariner's compass had not been invented, America could never have been discovered; and if America, and the passage to India by the Cape of Good Hope, had never been discovered, cotton would never have been brought to England; and if cotton had never been brought to England, the English people would have been as badly off for clothing as the people of the middle ages, and the millions of working men and women, manufacturers of cotton, and dealers in cotton goods, would have been without employment.

Astronomy, therefore, and navigation, both sciences the results of long ages of patient inquiry, have opened a communication between the uttermost ends of the earth; and therefore have had a slow, but certain effect upon the production of wealth, and the consequent diffusion of all the

necessaries, comforts, and conveniences of civilized life. The connection between manufactures and science, practical commerce and abstract speculation, is so intimate that it might be traced in a thousand striking instances. Columbus, the discoverer of America, satisfied his mind that the earth was round; and when he had got this abstract idea firmly in his head, he next became satisfied that he should find a new continent by sailing in a westerly course. The abstract notion which filled the mind of Columbus that the earth was a sphere, ultimately changed the condition of every living being in the Old World that then existed, or has since existed. In the year 1488, the first geographical maps and charts that had been seen in England were brought hither by the brother of Christopher Columbus. If these maps had not been constructed by the unceasing labors of men in their closets, Columbus would never have thought of discovering "the unknown land” which occupied his whole soul. If the scanty knowledge of geography which existed in the time of Columbus had not received immense additions from the subsequent labors of other students of geography, the United States would not have thousands of merchant ships ready to trade wherever men have any thing to exchange-that is, wherever men are enabled to give of their abundance for our abundance, each being immensely benefitted by the intercourse. A map now appears a common thing, but it is impossible to overrate the extent of the accumulated observations that go to make up a map. An almanac seems a common thing, but it is impossible to overrate the prodigious accumulations of science that go to make up an almanac. With these accumulations, it is now no very difficult matter to construct a map or an almanac. But if society could be deprived of the accumulations, and we had to re-create and remodel every thing for the formation of our map and our almanac,