finishing of the observatory would be sufficient to furnish the funds to meet all engagements. The work was pushed rapidly forward. In February 1845 the great telescope safely reached the city; and in March the building was ready for its reception." Unfortunately, just at this time, when his private means were exhausted, Professor Mitchel's professorship was brought, in a very summary manner, to a temporary close, in consequence of the college edifice being burned to the ground. To recruit his means without abandoning the cause of astronomy, he gave courses of lectures in the chief cities of the United States, meeting with well-deserved success.

The observatory thus erected achieved useful, though not very striking results. An observatory which was erected a year or two later took so quickly the leading position, so far as the actual study of the heavenly bodies was concerned, that the progress of the Cincinnati astronomers, as indeed of most of the astronomers of the United States, received less attention than otherwise might have been the case. I refer to the Observatory at Harvard (Cambridge, Mass.). Here one of the first equatorials ever made by Merz was erected; and by means of it W. C. Bond and his son Geo. P. Bond made highly interesting additions to astronomical knowledge. The seventh satellite of Saturn (eighth and last in order of discovery) was detected, the dark ring rediscovered and found to be transparent; important drawings of nebula were made, and many other observations were effected, under the administration of the Bonds. Later, under Professor Winlock, the Harvard Observatory has been distinguished by the excellence of the mechanical arrangements adopted there, and by M. Trouvelot's admirable drawings of solar spots and prominences of the planets Jupiter and Saturn, and of various details of lunar scenery.

In passing, I may note that at Harvard, as indeed elsewhere in America, others than professed astronomers have achieved very useful astronomical work. As Professor Mayer, of the Stevens Institute, Hoboken, has turned his marvellous ingenuity in devising new methods of physical research to astronomical inquiries, so Professor Cooke of Harvard, whose special subject is chemistry, made a most important astronomical discovery, which has since been ascribed to Janssen, who, later (though independently and by another method) effected it. Professor Cooke made a series of observations on those bands in the solar spectrum which are due to our own atmosphere, with the object of ascertaining whether they are due to the constant constituents of the air, or to the aqueous vapour which is present in the air in variable quantity. Combining hygrometric with spectroscopic observations, he found that when the air is moist. these bands are more clearly seen than when the air is dry, and

by systematic observations so definitely ascertained this relation as to prove beyond all manner of doubt that the bands are due to aqueous vapour. Unfortunately, though his results were published in America, they were not published in such a way as to attract notice in Europe, and accordingly European astronomers remained ignorant of the most important fact dis covered by Cooke until they had rediscovered it for themselves.

The Observatory at Ann Arbor, Michigan, was erected in 1854, chiefly through the exertions of Chancellor Tappan, of the Michigan University. Dr. Brünnow, our present Astronomer Royal for Ireland, was for a long time director of this observatory. It is at present under the able control of Professor Watson, who has added nearly a score of planetoids to the known members of the solar family.

The Observatory of Dartmouth College, Hanover, N.H., illustrates in a remarkable way the energy and zeal with which college observatories are managed in America. It would be difficult to name any observatory in this country where observations of greater interest, as respects the physics of astronomy, have been made than those effected by Professor Young with the 9-inch telescope constructed by Alvan Clark for the Dartmouth College; or than the supplementary observations made by Young with a powerful telescope conveyed to an elevated pass in the Rocky Mountains. Amongst his results may be specially mentioned-first, the observations of the most remarkable solar outburst yet witnessed, an outburst during which the glowing hydrogen of the prominences was driven to a height of at least 200,000 miles from the surface of the sun; and, secondly, the identification of more than 250 lines in the spectrum of the solar sierra.

And as the most interesting and characteristic observations yet made upon solar prominences are due to Professor Young of Dartmouth Observatory, so the most accurate and detailed drawings yet made of sun-spots are those by Professor S. Langley, of the Alleghany Observatory, near Pittsburgh.

At Chicago, a very fine telescope, 18 inches in aperture, by Alvan Clark, has been erected; but, owing to pecuniary difficulties consequent on the great fire (followed by the commercial depression which has recently affected the United States), that observatory has suffered considerably from the want of a properly remunerated director. The Astronomical Society of Chicago has done its best to set matters straight, but differences have arisen which have marred their efforts. In the meantime Mr. S. W. Burnham, of Chicago, has shown admirable zeal and skill in the systematic observation of double stars, having discovered and measured more than 450 of these objects (all of a delicate and difficult nature).

But, indeed, it would be hopeless to attempt, in the short space available to me here, to give any sufficient account of the labours of American astronomers, whether attached to government or state observatories, or working independently. Of the latter, and in my opinion not the least important class, I need cite only Drs. Rutherford and H. Draper, the former of whom. besides making other extremely important contributions to astronomy and physics, has produced celestial photographs admittedly better than any obtained on this side of the Atlantic, while the latter at an earlier period achieved results in celestial photography which were far superior to any obtained at that time, or for many subsequent years. The advice and assistance rendered by Dr. H. Draper to the astronomers to whom was entrusted the preparations for the recent transit, was most deservedly commemorated in a medal which the American government honoured itself by awarding to him.

The most striking feature in the contributions made by Americans to astronomy appears to me to be the skill shown in noting the essential points to be aimed at, and the fertility and readiness of resource exhibited as the work proceeds. In England, students of astronomy are too much in the habit of following conventional rules and wasting time over unnecessary preliminaries. An American astronomer notes that some particular observation is wanted, and directs his efforts to making that observation, not considering it necessary in the first place to go over ground already repeatedly traversed by others.

I have been sometimes asked whether officialism is as rampant in America as in England in matters scientific. American scientific officials have assured me that it is, or rather (for they have not worded the matter precisely in that way) they hold that official science is properly (as they consider) paramount in their country. I was gravely assured in Washington, for instance, that the course which I had pursued in England with reference to the suggested official schemes for observing the transit of Venus in 1874 would never have been tolerated in America, despite the fact that the course actually followed by American official science was precisely that which I had advised. It was the principle, so an eminent American official scientist assured me, which was in question, and no American would have been suffered to oppose as I did the course advised by the chief official astronomer. What would have happened to such an unfortunate was not clearly indicated; and I must confess that all I heard outside official scientific circles in America suggested to me that any mistake made by official science would be commented upon even more freely in America than in England, and quite as safely. In fact, I had reason to believe that the warmth of my own welcome in America was in no small degree

due to the fact that having first proved the justice of my views, I had not been afraid to maintain them publicly against the powers that were until the proper course was adopted.

One other point remains to be noticed--the influence, namely, of religious scruples upon scientific progress and research in America. Here I must admit that I was somewhat disappointed. I expected to find America a long way in advance of England. But with some noteworthy exceptions, especially in the west, America seems to me to be behind England in this respect. It is only here and there in England-in the Boeotian corners, so to speak, of this country-that the community opposes itself to advanced scientific ideas to the same extent as in some of the leading cities of the United States. This is partly due to two opposite influences-the Puritan element of the American population on the one hand, and the Roman Catholic element on the other. Progress, however, is being steadily made in this as in other matters. Indeed, it has been rather because America began later to bestir itself in the encouragement of free search after truth, that she is at present behind England in this respect. Judging from experience in other matters, she will move rapidly now her progress has begun, and will soon occupy the position to be expected from the natural freedom and independence of the American mind. It need hardly be said, that in America as in Europe, such contest as arises from time to time between religion and science has its origin entirely from the side of religion. There, as here, religion (so-called) attacks and denounces discoveries inconsistent with the views which the orthodox had been accustomed to advocate; and there, as here, when there is no longer any choice, the orthodox quietly accept these discoveries as established facts, expressing a naïve astonishment that they should ever have been thought in the least degree inconsistent with received opinions.

364

ON THE PROGRESS OF AERONAUTICS.

By FRED. W. BREAREY,

HON. SEC. TO THE AERONAUTICAL SOCIETY OF GREAT BRITAIN.

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10 the casual observer of a balloon which floats away from his presence into the dim distance, amidst the cheers of the crowd, and from thence into the solitude of an infinite space, it is hard to believe that its utility is doomed to the limit of mere flotation. He thinks that there is either an immense amount of apathy or else a lamentable display of ignorance among mechanical minds which prevents their energies being concentrated upon the navigation of the balloon. This is of course the popular judgment, yet it is only partially erroneous. The late Franco-German war afforded an opportunity for energy and engineering capabilities, and we know something of what balloons are capable, though perhaps not the uttermost, especially when accompanied by unlimited expenditure. The termination of the war interfered with certain designs, for the accomplishment of which M. de Fonvielle had escaped from Paris in a balloon. As he was the chief of the Aeronautical Department, he hoped to collect at Lille all the balloons which had left the French metropolis, and he himself came to England with the object of consulting as to the best means of aiding the return journey.

When the armistice was concluded six balloons had been collected at Lille, waiting for a favourable wind. By the aid of a small propelling force M. de Fonvielle believed that, starting with a fair wind, he would be able to deviate a few degrees from the current if necessary. It is highly probable that the return would have been effected, as Paris was the centre of a circle of investment of twenty miles diameter. With a favourable wind a sailor named Gally, with three others, left Paris on Nov. 12, with the intention of reaching Bordeaux, and they descended at Gondreville, near Bordeaux.

There is an anomalous incidence connected with the subject which would seem to favour the advocates of balloon propul