Bering's Report being written in archaic and badly spelled Russian, with a singular disregard of punctuation and other literary niceties, the translation presented unusual difficulties, in solving which I have had the kind coöperation of that excellent Russian scholar Mr. J. Curtin. I am indebted to the Reverend Father Richards, president of Georgetown University, and Father Maas of Woodstock College, Md., for valuable information in regard to the church festivals and saints, whose names were utilized in the nomenclature of Bering's new discoveries. To Mr. Marcus Baker, Messrs. Gannett and Woodward, and Mr. C. C. Darwin of the Geological Survey; Dr. S. Hertzenstein of the Zoological Museum of the Academy of Sciences, St. Petersburg; Baron Nordenskiöld of Stockholm, and Baron Robert Klinckofström; Drs. Holm and Stejneger of the U. S. National Museum, and Prof. Julius Olson of Madison, Wisconsin, I am indebted for numerous favors and courteous assistance, and to all of these gentlemen I desire to express my thanks.
In conclusion I desire to state that I am well aware this paper cannot be regarded as a finality, but as a contribution to the geographical history of North America it will not be without its value, while the fact that I have myself spent parts of three summers in scientific exploration of the coast visited by Bering and first charted by him, has greatly helped me in my discussion of minor details of his work.
INSTRUMENTS AND METHODS.
In considering the work done by the expedition it is very necessary to bear in mind the character of the instrumental outfit, if any, which they might have possessed, and the state of the science of navigation at the time.
When Bering and his two cartographers left St. Petersburg in February, 1725, the astronomical instrument in use by navigators was the Davis quadrant or "backstaff," in which the sun's altitude was measured by sighting without a telescope or tube on the shadow cast by the sun from one projection of the instrument upon another, the observer's back of course, being turned to the luminary. The only alternative to this was the still older astrolabe with which the observer had to look along the two lines of his angle at the same time, and which also depended upon sights or spurs attached to a frame. The reflecting quadrant of Hadley was not invented until 1731 and telescopes were not used on the instruments of navigation until somewhat later. There were no chronometers or reliable watches or clocks for use in dividing intervals of time. Even after the Hadley quadrant came into use, time was noted by a pendulum vibrating seconds, which could not be used on ship-board.
A futile attempt had been made by means of tables of variation of the compass to determine the longitude by comparison with observed variation in the field. Results by this method approached the truth accidentally, if at all. Lunar observations were the only means of getting an approximation to the longitude except the occultations of Jupiter's satellites, both methods being impracticable on board ship, with the instruments then employed.
In 1731 the astronomer Halley proved2 that at that date it was still impossible to find the longitude correctly by the moon, the lunar tables being so inaccurate that an error of several hundred miles was quite possible and an accurate determination would depend upon the respective errors of instrument, observation and the lunar tables happening to balance one another. Halley ventured to express the hope that the tables may be so amended that an error may scarce ever exceed three minutes, which would correspond to a degree and a half of longitude, amounting at the equator to a distance of a little less than one hundred miles. Messerschmidt, who preceded Bering as an explorer of Eastern Siberia, was according to Middendorf (Sib. Reise, iv. 1, p. 56) thirty-two degrees out in his determination of the longitude, and the eastward extent of Asia in this region was underrated by that amount or thereabouts, on many maps.
2 Phil. Trans. 1731, No. 421.
One other means of approximating to the meridian remained, in the observation of eclipses. This from the comparative rarity of these occurrences in the case of the sun and moon, could with the imperfect instruments of those days be available but seldom. Owing to the difficulty of determining the exact time of the first and last contacts the longitudes computed by these observations were liable to quite as great inaccuracy as those computed from the lunar tables. Still an ordinary spyglass would enable an observer to note the time within a minute or two, and, if he was possessed of the local time, a simple comparison with the observed time of the eclipse in some locality where the longitude was known would give a fairly good determination, considering the instruments and methods of those days. Of the four eclipses of the moon occurring in 1728-9 two might have been observed without difficulty by Bering, one would have been invisible to him, and one might barely have been noted, but in all probability was not observed by him. In none of the published reports of the expedition is any mention made by Bering or his officers of the occurrence or observation of an eclipse, which seems very singular if by such an observation he was enabled to correct an error of 30° in the longitude of northeastern Siberia. However, Middendorf states (Sib. Reise, iv. 1, p. 56) that "Bering and his lieutenant in the years 1728 and 1729 observed in Kamchatka3 two eclipses of the moon," by which they corrected the longitude. He gives no authority for this statement.