Recently photographs of Jupiter have been secured at Flagstaff, by the new methods there of planetary photography, showing a surprising amount of detail. The wisps come out with certainty, and the white spots, which are such a curious feature of the disk, have also left their impress on the plate. Not the least of the services thus rendered by the camera is the accurate positioning of the belts made possible by it. Micrometric measures are all very well when nothing better is attainable, but any one who has made such upon a planet’s disk swinging like a lantern in the field of view under a variety of causes instrumental and optical, knows how encumbered they inevitably are with error. To have the disk caught and fixed on a plate where it may be measured at leisure and as often as one likes, is a distinct advance toward fundamental accuracy. Measures thus effected upon the Jupiter images of 1909 proved the bright equatorial belt to lie exactly upon the planet’s equator when allowance was made for the tilt of the planet’s axis toward the Earth. This showed that the aspect of the planet toward the Sun had no effect upon the position of the belt. Jupiter’s cloud formation, therefore, is not dependent, as all ours are, upon the solar heat. A like indifference to solar action is exhibited in the utter obliviousness of the belts to day or night. To them darkness and light are nugatory alike. They reappear round the sunrise edge of the disk just as they left it when they sank from sight round the sunset one, and they march across its sunlit face without so much as a flicker on their features. Yet this seeming immobility from moment to moment takes place in what is really a seething furnace, the fiery glow of which we catch below the vast ebullition of cloud in the cherry hue of its darker portions. Distance has merged the turmoil into the semblance of quiescence and left only its larger secular changes to show. Even so the Colorado River from the brink of the Grand Cañon is seen apparently at rest, the billows of its rapids so stereotyped to stability one takes the rippled sand bank for the river and the billows of the river for the ripple marks of its banks. At twice the distance of Jupiter we cross the orbit of Saturn. Here the ringed planet, with an annual sweep of twenty-nine and a half of our years, pursues his majestic circuit of the Sun. Diademed with three or more circlets of light and diamonded by ten satellites, he rivals in his cortège that of his own lord. In some ways his surpasses the Sun’s. For certainly his retinue is the more spectacular of the two; the more so that it is much of it fairly comprised within a single glance. Very impressive Saturn is as, attended thus, he sails into the field of view. [Illustration: SATURN—A DRAWING BY DR. LOWELL, SHOWING AGGLOMERATIONS.]