Ships & Ways of Other Days

by E. Keble Chatterton

After the Woodcut of Hansen Burgmair.

And since it was obvious that discovery had to be made by traversing long expanses of ocean, and that this could only be done by a sound knowledge of navigation, those in authority were not slow to realise that lectures and instruction on this subject at home meant presently an increase of territory and wealth across the seas. Prince Henry on his promontory had been the first to grasp this. Now also Charles V not only established a Pilot Major for the examination of those who sought to take ships to the West Indies, but also founded a lecture on the art of navigation which was given in the Contractation House at Seville. Those anxious to qualify as pilots had to learn thoroughly the use of the astrolabe and quadrant, and obtain a thorough grasp of the theory and practice of sailing a ship from one port to another out of sight of land. For this instruction they had to pay fees, but it more than repaid them many times over when they were able to bring back such valuable commodities. Furthermore, as experience gains knowledge, so every voyage taught them something of their art which hitherto they had not known—the direction of a current, the state of the moon when high tide occurred at such and such an hour, the depth of those new harbours they had entered, the position of the outlying shoals, the landmarks on shore, the temper of the natives, the kind of commodities which could be obtained in the districts, and so on. The pilots brought all these details home at the end of every voyage, made the necessary corrections in the charts (and this not by choice, but by compulsion), so that always there was being compiled a set of sailing directions and an ever improving bundle of charts which were simply invaluable to State and seamen alike.

Thus also there came to be published treatises and manuals on the seaman’s art, for the instruction of a community that numbered very few sailors in proportion to its landsmen. Such authors as Martin Cortes, Alonso de Chavez, Hieronymo de Chavez, Roderigo Zamorano in time wrote these works, and their influence not merely on Spain, but upon England, was considerable, until the English seamen of the time of Elizabeth had produced such nautical experts of their own that they were able to write better books themselves. But even prior to that time England had begun to see the wisdom of Spain; and Henry VIII, following the example of Charles V, “for the increase of knowledge in his Seamen, with princely liberalities erected three severall Guilds or brotherhoods, the one at Deptford here upon the Thames, the other at Kingston upon Hull, and the third at Newcastle upon Tine.” So, indeed, states Hakluyt. That at Deptford was licensed in 1513, “in honour of the Holy Trinity and St. Clement in the Church of Deptford Stronde for reformation of the Navy lately much decayed by admission of young men without experience, and of Scots, Flemings, and Frenchmen as loadsmen.” Navy is used here in its literal sense, meaning shipping as a whole. The word “loadsmen”—otherwise “leadsmen”—was the customary expression in the North of Europe for pilot. To this day the Dutch word for pilot is “loods,” “lood” being the Dutch for lead. What does this signify? It shows—does it not?—that until, thanks to Spain, the astrolabe began to be used in Northern Europe, the pilot was not so much he who found his way by fixing his position from the heavenly bodies, but he who felt his way by the sounding of the lead. In a sentence, then, whilst of course the lead and line are essential even to modern navigation, yet historically they belong to the Middle Ages and right back to Greece and even earlier; while the astrolabe and the finding of a ship’s latitude are essentially the beginning of that new order of things which we have already noted. So long as ships were content to do little more than coasting they had no need of an astrolabe; but as a lead and line are not much good to one who navigates the Atlantic to the West Indies, so the new species of voyaging coincided with the new instrument for ascertaining a ship’s position.

A Sixteenth-Century Astrolabe.

This instrument, in the S. Kensington Museum, is supposed actually to have been on board one of the ships of the Spanish Armada.

Astrolabe used by the English Navigators of the Sixteenth Century.

What, then, was the astrolabe? It was an instrument used for taking the altitude of the sun and stars. For two hundred years before it was used by the Christian seamen of the Mediterranean, it had been employed by the Arabian pilots in the eastern seas. The derivation of such a curious word is not without interest. The Arabic is “asthar-lab,” and this in turn came from the two Greek words, ἀστήρ and λαμβανω, meaning “to take a star.” It consisted of a flat brass ring, some 15 inches in diameter, of which an excellent illustration can here be seen. It was graduated along the rim in degrees and minutes, fitted with two sights. There was a movable index which turned on the centre and marked the angle of elevation. When the mariner wished to take the height of the sun with this instrument he proceeded as follows: The sun being near the meridian or south, the pilot observed the same until it reached its greatest height. Then, holding the ring on one of his fingers, he turned the alhidada up and down until he saw the shadow of the sun pass through both the sights thereof, being sure that the astrolabe hung upright. The astrolabe was best for taking the height of the sun when the sun was very high at 60, 70, or 80 degrees; for the sun, coming near “unto your zenith,” has great power of light for piercing the two sights of the alhidada of the astrolabe, and then it was not good to use the cross-staff (reference to which will be made below), because the sun hurt a man’s eyes and was also too high for the cross-staff. Furthermore the astrolabe, was a more correct method than that of the cross-staff.

It was thanks to the aid of Martin Behaim, a distinguished cosmographer who came to Lisbon to co-operate with the learned men there assembled, that an improved sea astrolabe was adapted for the purpose of determining the distance from the Equator, by means of the altitude of the sun or stars at sea. There had, indeed, been in use for some time a land astrolabe for finding the latitude of a place, and it was but a natural advance that this instrument should be adapted for use on board ship, so that the mariner might be able to ascertain his position on the vast expanse of trackless ocean. We are all most ready to admire and extol the men and the ships which made such daring voyages and discoveries in the past; but I submit that nothing like adequate recognition has been paid to the essential value of the astrolabe and cross-staff, or their successor, the modern sextant. Even if in those days which marked the close of the Middle Ages there had suddenly been invented and built a whole fleet of turbine steamships with capable crews, yet still without the instrument of finding latitude they could have had only vague ideas as to their position and would only have been able to produce unsatisfactory charts. Indeed, as a modern writer has remarked, it was this improved sea astrolabe which “removed the last doubt in Columbus’s mind as to the possibility of carrying out his plans of discovery.”