The author is most familar with the Leitz microscopes, which are furnished by Wm. Krafft, 411 West 59th St., New York city, or by the Franklin Educational Co., 15 and 17 Harcourt St., Boston.

The Leitz Stand, No. IV., can be furnished duty free (for schools only), with objectives 1, 3, and 5, eye-pieces I. and III., for $24.50.

Stand 'A,' the same stand as the 'AAB,' without joint and with sliding tube coarse adjustment (as in the Leitz Stand IV.), and with three eye-pieces and 2/3-inch and 1/4-inch objectives, is furnished for $20.40.