phantly they have overcome them. Nor should it be forgotten in this connection that the great Lick telescope as well as the Washington telescope is of American manufacture. Both are the products of the consummate optical skill of Messrs. Alvan Clark, of Massachusetts. Those who provided these grand instruments, those who made them, those who used them, and the nation which owns them, are all to be sincerely congratulated on the splendid results of their joint efforts.
The orbit of Jupiter so nearly resembles a circle that the distance from the earth to the planet does not greatly alter. Accordingly there is not much variation in the distance from the earth to the planet at one opposition and another. It does so happen that in the opposition through which Jupiter passed in 1892, the actual distance attained was almost the smallest possible. Even that, however, is nearly four times as great as the distance from the earth to the sun. In the case of Jupiter, the most important question, so far as the advantages for observation are concerned, is the season of the year when the opposition takes place. For observations of a planet it is specially desirable to have the body as high as possible in the heavens. The atmospheric difficulties, which are always so embarrassing to the astronomer, are lessened with every increase of the altitude. This consideration will show how the opposition referred to offered exceptionally favourable advantages for the observation of Jupiter. As the great planets move in planes which are nearly coincident with the ecliptic, it follows that the best time for observing the planet will be during the winter season. Of course, the most suitable moment, so far as altitude is concerned, would be when the oppo-
