THE POPULAR SCIENCE MONTHLY.
thing that is going on in this world. It underlies agriculture; it is the basis of manufactures; it is the key to geology; meteorology depends upon it; it explains domestic processes; is the foundation of physiology and biology, and, moreover, astronomy has lately courted its alliance, and arrived at the most splendid results by its aid. Certainly a magazine which chronicles the progress of this most progressive of the sciences should have a vigorous support, while the reputation of its accomplished editors is the best guarantee of its trustworthy character.
The New Planet Vulcan.—The observation of certain disturbances in the motion of the planet Mercury, and the appearance: it particular periods of well-defined circular black spots, passing rapidly across the disk of the sun, have led astronomers to suspect the existence of a ninth planet, interior to Mercury, and with a period of revolution, according to M. Leverrier, of 19.70 days. Such a spot was seen to cross the sun on March 26, 1859, the observer being a French physician named Lescarbault, who thereupon claimed the discovery of the planet, to which the name of Vulcan was assigned. It should be added, however, that other observers had previously witnessed a similar phenomenon. The spot was again seen by Mr. Lummis, of Manchester, on the 20th of March, 1862. From calculations based upon these and other observations, Mr. Hind, of the Twickenham Observatory, England, in a letter last year to the London Times, suggested 10 o'clock a. m. on the 24th of March, 1873, as the time when a conjunction of the supposed planet with the sun might be expected to occur. "If the hypothetical body," says Mr. Hind, "is not found upon the sun's disk at that time, it will be, I think, a sufficient proof that my surmises are incorrect." Prof. Kirkwood, in a recent letter to the Tribune, states that "Mr. Cowie has just reported the appearance of such a spot on the sun at Shanghai, China, on the morning of March 24, 1873, thus fulfilling the prediction of Mr. Hind, and rendering the existence of such a planet reasonably certain. Prof. Kirkwood's calculations, as given in the letter above quoted, make its sidereal period 34 days, 22 hours, 31 minutes. In a subsequent letter, Prof. Kirkwood calls attention to the fact that similar spots have been observed on the sun, at other dates, which cannot be referred to the same asteroid, and he thence infers the existence of a zone of minor planets within the orbit of Mercury. Why none of these have ever been seen during total eclipses of the sun he explains as follows:
"It is well known that a marked difference obtains between the light-reflecting capacities of the various planets of our system. Mercury, for instance, is in this respect very much inferior to Venus and Jupiter. (See Proctor's "Other Worlds than Ours," p. 67.) The difficulty, then, in regard to the invisibility of these asteroids when the sun is eclipsed, may be obviated by supposing their surfaces so constituted as to reflect but a small portion of the sun's light."
Education in Sierra Leone.—Mr. John Pope Hennessy, ex-Governor of Sierra Leone, delivered recently, before the London Society of Arts, an admirable lecture on "the British Settlements in Western Africa." We give a synopsis of that part of the discourse which treated of the state of education. It is the avowed purpose of the British Government to train the natives to habits of self-control, so that they may be finally suffered to govern the country themselves. But that no great progress has been made in the preliminary work of education is admitted on all sides. In 1869, "education was most inadequately provided for" in Sierra Leone. In 1870 the "conspicuous listlessness and inattention of the scholars" are noted by the Director of Public Instruction. In 1872 Mr. Hennessy was himself convinced that the system in use was only "an incentive to the formation of a thoughtless, idle, and indolent character." And at Cape Coast matters were still more unpromising. In 1872 the government chaplain calls loudly for compulsory education, because he cannot induce the scholars to attend to their duties.
That the fault does not lie with the natives is very satisfactorily shown by Mr. Hennessy. On his second visit to Lagos,