Preparation for lecturing.

The plan of organization contemplates a series of free lectures, particularly during the session of Congress. These will be commenced as soon as the building is ready for the purpose. This part of the plan also cannot be put into full operation until after the building is completed. A number of gentlemen have consented to favor us with their services. Men of talents, however, cannot be expected to leave their homes and subject themselves to the expense of visiting Washington, and to the trouble of preparing a course of lectures, without a proper remuneration. It will be necessary, therefore, that an annual appropriation be made for this purpose. The amount, however, must necessarily be small until the building is completed, or until all the interest of the fund can be devoted to the primary objects of the Institution. Besides this, the lecture-room in the east wing, now finished, will scarcely hold more than five hundred persons, while the one in the main building is intended to accommodate twice as many.

Donation.

Dr. Robert Hare, of Philadelphia, having resigned the chair of chemistry in the University of Pennsylvania, which he had filled with honor to himself and his country for nearly thirty years, has presented to the Smithsonian Institution the instruments of research and illustration, collected and used by himself during his long and successful scientific career. Many of these instruments are the invention of the donor, are connected with his reputation, and belong to the history of the science of our day. The gift is important, not only on account of its intrinsic value, but also as establishing a precedent of liberality, which we trust will be frequently observed by others, as well as being an expression of Dr. Hare's approbation of the plan and confidence in the stability of the Institution. A number of other donations have been received, of which a list, with the names of the donors, will be given in a subsequent report.

In view of what has been stated in the foregoing report, the Secretary trusts that the Board of Regents will be satisfied, if ever they had any doubts on the subject, that the plan adopted is one well calculated to carry out the benevolent intentions of the donor, of increasing and diffusing knowledge among men; and that a satisfactory answer has been given to the question frequently asked, namely, When is the Institution to begin? It will be seen that it has commenced the most important part of its operations, and the results are now in progress of dissemination in every part of the civilized world.

Respectfully submitted,

JOSEPH HENRY, Secretary of the Smithsonian Institution.

THIRD ANNUAL REPORT

Of the Secretary of the Smithsonian Institution, for the year 1849.

To the Board of Regents of the Smithsonian Institution:

GENTLEMEN: In accordance with the resolution that the Secretary shall present at each annual meeting of the Board of Regents an account of the operations of the Institution during the past year, I respectfully submit the following.

Agreeably to the scheme of finance adopted by the Board, the greater portion of all the income of the Smithsonian fund is at present devoted to the erection of the building; and until this is paid for, the money which can be appropriated to the active operations of the Institution will be comparatively small, not only small in proportion to the demands made upon it, but small in reference to the results which the public generally expect it to produce. It is believed, however, that a proper consideration of the facts presented in the following report will warrant the conclusion, that the Institution, during the past year, has been gradually extending its sphere of usefulness, and successfully bringing into operation the different parts of its plan of organization.

It will be recollected that the several propositions of the programme were adopted provisionally, and it is gratifying to be able to state that experience thus far has indicated no important changes. The general plan has continued to receive the approbation of the enlightened public both in this country and in Europe, and to increase general confidence in the power of the Institution to confer important benefits on our country and the world.

In presenting the different operations of the Institution, I shall adopt, as in my last report, the principal divisions of the programme:

1st. Publication of memoirs in quarto volumes, consisting of positive additions to knowledge.

2d. Institution of original researches, under the direction of competent persons.

3d. The publication of a series of reports, giving the present state and progress of different branches of knowledge.

4th. Formation of a library and museum of objects of nature and art. 5th. Lectures.

Publication of Memoirs.

Agreeably to the plan of the Institution, these memoirs are intended to embody the results of researches which could not otherwise be readily published, and are to be distributed to societies, public libraries, and other institutions. An account of the first memoir was given in the last report. It relates to the ancient monuments of the Mississippi valley, and occupies an entire volume. It has been presented, as far as opportunity would permit, to the principal literary and scientific societies of the world, to all the colleges and larger libraries of this country, and has everywhere

been received with much commendation. All the societies from which we have as yet heard, have declared their willingness to co-operate with the Institution, and to give us their publications in exchange, from which source our library has already been enriched with valuable

additions.

It is to be regretted that our means would not permit us to distribute the first volume more liberally than we have done, and that the price put upon the copies offered for sale has placed them beyond the reach of many persons desirous of obtaining them. This arose from the fact, that in order to remunerate the authors for the expense and labor bestowed on the memoir, they were allowed to strike off from the types and plates of the Institution an edition to be sold for their own benefit. To avoid risk of loss, the edition was a small one, and the price put at ten dollars. An occurrence of this kind will not happen again; for, although it would be desirable to pay authors for their contributions, yet it is now found that materials will be offered, free of all cost, more than sufficient to exhaust the portion of the income which can be devoted to publications. In printing the future volumes it will be advisable to strike off an extra number of copies for sale on account of the Institution, and to dispose of those for little more than the mere cost of press-work and

paper.

The second volume of Contributions is now in the press, and will consist of a number of memoirs which have been submitted to competent judges and found worthy of a place in the Smithsonian publications. In this volume we have adopted the plan of printing each memoir with a separate title and paging. The object of this is to enable us to distribute extra copies of each memoir separately, and also to furnish the author with a number of copies regularly paged for his own use. will likewise enable us to classify the memoirs according to subjects. The following is a brief account of the memoirs contained in the second volume, so far as they have been reported on by the commissioners to whom they have been submitted:

It

1. A memoir on the planet Neptune, by Sears C. Walker.-An abstract of this memoir has been published in the proceedings of the American Philosophical Society, and has received the approbation of the scientific world. It presents the several steps of the discovery of an orbit which has enabled Mr. Walker to compute the place of the new planet with as much precision as that of any of the planets which have been known from the earliest times. Starting from the observations of the motion. of the planet during a period of about four months, Mr. Walker calculated an empirical orbit, which enabled him to trace its path among the stars of the celestial vault through its whole revolution of 166 years. He was thus enabled to carry its position backward until it fell among a cluster of stars accurately mapped by Lalande towards the close of the last century; and, after a minute and critical investigation, he was led to conclude that one of the stars observed by Lalande on the night of May

*It is proper to state that a part of the researches given in this memoir was made during the author's connexion with the National Observatory, under the direction of Lieutenant Maury. An account of these will probably soon be published in the next volume of the records of operations of this observatory.

10, 1795, was the planet Neptune. This conclusion was rendered almost certainty by the observation, made on the first clear night, that all the stars in the cluster above mentioned were found in place, except the one previously fixed upon as the new planet. Some hesitation was created, however, by noting that the missing star in Lalande's maps was marked as doubtful. In order to settle this difficulty, the original manuscript of the astronomer deposited in the Observatory of Paris was referred to. It was then found that Lalande had twice observed the same star; and not finding the right ascension and declination each time the same, and not dreaming it was a planet, he selected one of the observations for publication, marking the position indicated doubtful The planet had moved during the interval of observation, and thus produced the discrepancy. By allowing for the movement during the time elapsed, the two observations precisely agree. There could, therefore, be no longer any doubt that this star, observed and mapped fifty years ago as a fixed star, was in reality the planet Neptune. Mr. Walker, availing himself of this discovery, had now a series of observations embracing not a few months of the motion of the planet, but which carried it back fifty years. From these data he was enabled to deduce a pure elliptical orbit, or one which the body would describe were there no other planets in the system. This orbit has been investigated by another of our countrymen in a series of profound and beautiful researches, adding much to our knowledge both of Neptune and Uranus. I allude to the labors of Professor Peirce, of Cambridge.

It is well known that the planet Neptune was discovered by mathe matical deductions from the perturbations observed in Uranus, and that Leverrier and Adams, the independent authors of this discovery, not only pointed out the direction in which the unseen planet was to be found, but also, from a priori considerations, gave the dimensions, form, and position of the orbit it describes around the sun. The direction indicated was the true one, but the elements of the orbit were widely different from those subsequently found to belong to the actual orbit of the planet. Professor Peirce submitted the data used by Leverrier and Adams to a new and critical examination, and succeeded in discovering the cause of their error, and of verifying the conclusions of Mr. Walker. He afterwards proceeded to consider the inverse problem, viz that of deducing the perturbations which Neptune ought to produce in the planet Uranus. His final results gave a perfect explanation of all the anomalies in the motions of Uranus, and furnished the data, for the first time since its discovery in 1781, for correct tables for determining its position in the heavens. Professor Peirce also investi gated the action of all the other planets on Neptune, and his results enabled Mr. Walker, by applying them to his elliptical orbit, to compare the actual with the calculated place of the planet. This led to a further correction of the elliptical orbit, and a more perfect table of calculated places. In this way, by a series of profound and beautiful investiga tions, alternately combining the data of observation with theoretical considerations, these two astronomers have perfected our knowledge of the motion of the most distant planets of our system, and furnished the means of giving their past and future position through all time. The details of Mr. Peirce's paper have not yet been prepared for the press.

They will probably be given in due time to the world as a part of the Smithsonian Contributions.

The investigations mentioned in the foregoing account have been attended with very laborious arithmetical calculations. A small appropriation has been made to defray, in part, the expense of these. Indeed, without the aid thus given, the discoveries we have related would scarcely have been made-at least at this time, and in our country.

2. The next memoir is An account of the discovery of a Comet by Miss Maria Mitchell, of Nantucket, with its approximate orbit, calculated by herself. The honor of this discovery has been duly awarded to the author. A medal has been presented to her by the King of Denmark, and the comet itself is now known to astronomers in every part of the world by her name. From the peculiarities of the case, the Executive Committee recommended that a small premium be presented to Miss Mitchell.

3. The third memoir is On a new method of solving Cubic Equations, by Professor Strong, of New Brunswick, New Jersey; a purely mathematical paper, which has been pronounced an interesting addition to that branch of science.

4. The fourth memoir is A contribution to the Physical Geography of the United States. It presents a section, from actual surveys, of the descent of the bed of the Ohio river from its source, in the State of New York, to its mouth, on the Mississippi. By a series of observations and elaborate calculations, the author exhibits the amount of water which passed down the river during a period of eleven years prior to 1849. This, compared with the amount of rain which fell during the same time on the surface drained by the river, gives a series of interesting results in reference to evaporation.

It also contains a proposition for improving the navigation of the Ohio, founded upon data given in the preceding part of the memoir. Whatever may be the result of the plan here proposed, this memoir has been recommended for publication as a valuable addition to the physical geography of the United States. The author is Charles Ellet, jr., the celebrated engineer of the wire bridges over the Niagara and Ohio rivers. Another memoir is promised by the same author, which will be a continuation of the same subject.

5. The fifth memoir is contributea by Dr. Robert Hare, of Philadelphia, and is intended to elucidate the remarkable phenomena exhibited at the great fire in the city of New York on the 19th of July, 1845, during which two hundred and thirty houses were destroyed, containing merchandise amounting in value to sixty-two millions of dollars. "A series of detonations, successively increasing in loudness, were followed by a final explosion, which tore in pieces the building in which it took place, threw down several houses in its vicinity, and forced in the fronts of the houses on the opposite side of the street." These effects were attributed to gunpowder, though the owner of the building in which the explosion occurred declared that none of this article was present, but that the house contained a large quantity of nitre, in connexion with merchandise of a combustible nature.

This memoir contains a series of investigations relative to the explosions which may be produced by heated nitre in connexion with carbon