PROPERTIES OF THE MAGNETIC NEEDLE.

It has been supposed that many of the ventures performed by the ancients at sea were only made during the day, the mariners anchoring during the night, never venturing far from land, or a depth of water too great for anchorage. This theory, I do not think, will bear very close inspection, as stormy weather and a lee shore would have rendered any great voyages impossible. The knowledge and practice of the ancients in mining and working the metals must have been considerable, as many of the writings of the fathers of literature will testify. The properties of magnetic iron ore, the load-stone of ancient and modern times, its faculty of not only attracting iron and steel, but of imparting its polar peculiarities to these metals, must have formed a long and curious study, and ages may have passed before some genius first tried and tested, or discovered its unvarying tendency, when so placed as to be little retarded in its movements, of turning and placing itself at right angles with the rising and setting of the sun, and pointing to the north. These first experiments must have been made after the ore had been brought to a metallic form and the metal shaped in the form of a needle, much in use in the olden time for their knitting, embroideries, tapestries and lace-work, for which the ancients of the higher order were so justly celebrated.

BY WHOM INVENTED.

Yet it is the common opinion, in our modern day, that the compass and its uses was the invention of Flavio Gioja, a citizen of the once famous republic of

Amalphi, very near the beginning of 1300 A. Many who wrote long years previous to this period, give abundant evidences of its knowledge and uses. Thus the great Spanish antiquary, Antonio de Capomany, and the famous Raymond Lully, in writings published as early as 1272 A. D., go to show the exact uses made of the compass in navigation. In one place Lully says: "as the needle when touched by the magnet naturally turns to the north;" and again, in another portion of his writings, he says: "As the nautical needle direct mariners in their navigation;" leaving us with the impression, as they were writing of periods many years anterior to 1200 A. D., that the little compass was in common use among mariners and "those who go down to the sea in ships."

In addition to the evident theoretical knowledge, of a portion at least, of the world's geography had by the Egyptian Ptolemies, they possessed maps and charts of all the regions known at that time.

The voyages performed by Hanno, Hippeas and Pythias, many years previous to the Christian era, were not accomplished without considerable knowledge of geography and navigation.

There is distinct mention made, in Chinese history, of the compass points, not only at the time mentioned above (2634 B. C.), but on down to 121 A. D., and again in 265 and 419 A. D. The best authorities state, that the compass was introduced into Europe in 1184 A. D., while some writers ascribe its discovery to Gioja, at the commencement of 1300 A. D. Dr. Gilbert states, that it was introduced into Italy, by Marco Polo, in 1295. There is also evidence of its use in France in 1150, in Syria about the same time, and in Norway previous to 1266.

HOMER'S KNOWLEDGE OF SHIP BUILDING.

Now toils the hero; trees on trees o'erthrown,
Fall crackling around him, and the forests groan.
Sudden, full twenty on the plain are strow'd,
And lopp'd and lighten'd of their branchy load.
At equal angles these disposed to join,

He smoothed and squared them by rule and line.
(The wimbles for the work, Calypso found,)

With these he pierced them, and with clinchers bound.

Long and capacious, as a shipwright forms

Some bark's broad bottom, to outride the storms,

So large he built the raft; then ribb'd it strong,
From space to space, and nail'd the planks along;
These formed the sides; the deck he fashioned last;
Then o'er the vessel raised the taper mast,
With crossing sail-yards dancing in the wind;
And to the helm, the guiding rudder joined;
With yielding osiers fenced, to break the force
Of surging waves, and steer the steady course.
Thy loom, Calypso, for the future sails
Supplied the cloth, capacious of the gales.
With stays and cordage, last he rigged the ship,
And, roll'd on levers, launch'd her in the deer.
POPE'S (Homer's Odyssey.)

In the quotations presented, from the "Odyssey" of Homer-who was writing at a time something over eight hundred years previous to the Christian era, and describing events that took place about 1200 B. C.—a familiarity, not only with ship building, but an astronomical knowledge, and its uses in navigation, is displayed, that may justly excite wonder and admiration. Of the 1,152 ships Homer describes in the Iliad, as carrying troops, and participating in the Trojan war, not one is mentioned as relying solely on oars as a propelling power. All are described as sailing vessels, and under the guidance of experienced sailors and navigators, whose knowledge of navigation descended from previous ages

in 1725, of a voyage of discovery to the Arctic Seas; discovered the straits that bear his name, and the separation between Asia and America (in second voyage of 1728), outlining and surveying the coast of Siberia. He made a third voyage in 1741, on a North Polar expedition, reaching about 69 deg. north latitude, but owing to stress of weather and sickness among his crews, was compelled to return; was wrecked on Behring Island, in 55 deg. 22 min. north latitude, 166 deg. east longitude, where he died, after going through all the hardships that could befall a castaway in the desolate Polar Seas.

BYRON, JOHN.-Born November 8th, 1723, and died April 10th, 1786. Served with Anson as midshipman; was wrecked off the Patagonian coast, and lived on a desolate island in that region for five years (1740-46); publishing a narative of his sufferings in 1768; was placed in command of an exploring expedition in 1764, making some important discoveries. As an accomplished sailor, he had few superiors, and as an author, met with success. His sons also were men of mark and ability, culminating in his grandson, Lord Byron, the poet.

CARTERET, PHILIP.-Was captain of the Swallow, one of the vessels under Samuel Wallis, which sailed from England on a voyage of discovery to the South Seas, August 22d, 1766; his second voyage was on private account, discovering and naming Gower and Carteret Isles, Queen Charlotte Isles, Pitcairn, etc., rediscovering and naming the Admiralty group, and returning to England in 1769.