was given, and a full stop made when a somersault was completed. A shutter was then a necessary part of the apparatus to cut off the light rays during the time the pictures were changing places. This was accomplished by a vibrating shutter placed back of the picture wheel, that was operated by the same draw-bar that moved the wheel, only the shutter movement was so timed that it moved first and covered the picture before the latter moved, and completed the movement after the next picture was in place. This movement reduced to a great extent the flickering, and gave very natural and lifelike representation of the moving figures."
The American Professor.—Prof. Joseph Jastrow looks upon the American college professor as constituting a type of which it would be hard to find a counterpart anywhere else. His situation has recently been fully discussed in one of the magazines, and Professor Jastrow, commenting on the views there expressed, asks if the environment of our professor gives to his services a maximum of intellectual and moral value, and if it tends to develop most easily and successfully his own resources, and to urge him to the fulfillment of that function in the community for which his talents and training qualify him. The author can not answer these questions in the affirmative. There are undesirable factors in the professor's environment "which obstruct his public usefulness equally with his private happiness." He is "the type of the great underpaid, and this lack of income is, for many reasons, to be regarded as a calamity. . . . It is quite true that it were a pity that in the colleges of all places high thinking and plain living should be quite divorced; but it is a greater pity that the living should perforce be so arduous as severely to tax the energies that make for high thinking." From an investigation of the financial status of the professor, Professor Harper has found that he is on a par as to that with conductors, foremen of works, etc., with an average income of about sixteen hundred dollars, and that as a mere matter of justice his salary should be raised by one half—a conservative estimate. The average American professor suffers as much from the want of proper leisure as from the lack of a proper income, and the evil effects of the two are similar in kind; for the necessity of supplementing his inadequate salary will often direct his efforts into channels that promise some prompt remunerative rewards, rather than in the direction of the development of his maximum efficiency as a member of the university and as a personal influence. "Investigation and research, originality and scholarship come only as the slowly ripened fruits of leisure."
Montana Sapphires.—The existence of sapphires in Montana has been known for several years, but first attracted serious attention about 1891, when companies were formed and claims were taken up and examined with a view to mining fur them. The sapphire region, according to Mr. George F. Kunz, extends for about six miles along the Missouri River, the central point being Spokane Bar, twelve miles east of Helena. Another region is between seventy-five and a hundred miles east of this, centering at Yogo Gulch. Mr. Kunz describes marked differences as existing between the sapphires from these two regions. All are of the same size, but they differ in crystallization, the Missouri River gems being prismatic, and those of Yogo Gulch largely rhombohedral. The value of these sapphires in jewelry can hardly yet be estimated. "Much beautiful material has already been obtained, but little of high value. Those from the Missouri bars had a wide range of color—light blue, bluegreen, green, and pink—of great delicacy and brilliancy, but not the deep shades of blue and red that are in demand for jewelry. As semi-precious or 'fancy' stones they have value, however. The Yogo Gulch Judith River region is more promising, the colors varying from light blue to quite dark blue, including some of the 'cornflower' tint so much prized m the sapphires of Ceylon. Others incline to amethystine and ruby shades. Some of them are 'peacock-blue' and some dichroic, showing a deeper tint in one direction than in another; and some of the 'cornflower' gems are equal to any of the Ceylonese, which they strongly resemble."
The Filtration of Milk.—The wide area over which milk is collected for supplying a large city renders it practically impossible