June, I905. ] Notes and Comments. 459 15,o5o lines to the inch, and with so little distortion than an expert spectroscopist in one of our universities, working with a Hilger spectroscope, which utilized the entire aperture of the replica, declared that he could discover no difference in defini- tion between it and an original quality A Rowland grating. A photograph of the E b region of the solar spectrum made with one of them in a Browning Student Spectroscope shown with good definition every b group line that appears in the Angstrom and Kirchhoff maps, and more than fifty lines be- tween E and b. The fact that these replicas are good enough for the most serious spectroscopic work, can be made at a comparatively low price, and may be handled freely by students in schools and colleges without risk of injury, leads me to think that the achievement is one of real importance. THE FRITZ MEDAL AWARDED TO LORD KELVIN. The first award of the John Fritz Medal, which was established by the professional associates and friends of John Fritz, of Bethlehem, Pa., on August 21, i902. his eightieth birthday, to perpetuate the memory of his achievements in industrial progress, has been awarded to Lord Kelvin. This award was made by the following board selected for the purpose: From the membership of the American Society of Civil Engineers: Robert Moore, Alfred Noble, Chas Warren Hunt. Chas. FIermany. From the membership of the American Institute of Mining Engineers: E. G. Spils- bury, James Douglas, Charles Kirehhoff. E. E. Olcott. From the member- ship of the American Soeiety of Mechanical Engineers: John E. Sweet, Robert W. Hunt, Samuel T. Wellman, James M. Dodge. From the mem- bership of the American Institute of Electrical Engineers: Carl Hering, Charles P. Steinmetz, Charles F. Scott, B. J. Arnold. The medal is of gold of the value of about $I00, and with it is presented a certificate' of the award. The medal was awarded to Lord Kelvin for "Cable Telegraphy and other General Scientific Achievements.--The Iron Age. DETERMINING MOISTURE IN STEAM. A method of determining the moisture in steam at atmosp,heric pressure' was described by Professor D. S. Jacobus, of Stevens Institute, in a recent paper read before the American Association for the Advancement of Sci- ence. A known weight of superheated steam at a given temperature was mingled with a known weight of saturated steam at atmospheric pressure. The steam, after the mixture, was still superheated and its temperature was .