Oil and Gas Inspectors To the Editor of THE SCIENTIFIC AMERICAN: May we ask you to insert in your publication a brief notice to the effect that the Bureau of Oil Conservation, Oil Division, United States Fuel Administration, is desirous of securing a combustion engineer for each of the following districts, who will act as an inspector visiting all plants within his district using fuel oil and natural gas : Boston, Providence, New York City, Philadelphia, Pittsburgh, Buffalo, Detroit, Chicago, Minneapolis, Tulsa, New Orleans and San Francisco? It is desirable to have these men act as volunteers where possible, but the Administration is prepared to pay a reasonable compensation for men who cannot afford to give their services to the Government. Only men who have had experience in fuel oil and natural gas combustion would be of value. W. CHAMPLAIN ROBINSON, Director of Oil Conservation. United States Fuel Administration, Washington, D. C. Mirror Surface on Blown-Out Bulbs To the Editor of the SCIENTIFIC AMERICAN: Your issue of March 30th contained a note on this subject by Dr. Julius E. Bach. The following note of a process described by Mr. Otto Stuhlmann in the Journal of the Optical Society seems to show that both the metallic filament and platinum terminals would tend to vaporize under certain conditions and form a mirror surface : "Mr. Otto Stuhlmann, Jr., describes a new method of making mirrors, applicable in the case of any metal, and to any material, varying from glass to paper. It is described as a distillation method, and 'the principles are simple, though the apparatus needed is a little complex. Briefly, the process is as follows: To produce a silver mirror on, say, glass, a horizontal silver wire is heated to incandescence by means of an electric current, and the glass to be silvered is placed about one inch below it. The whole apparatus being in a vacuum, the wire is drawn at a, uniform speed backwards and forwards across the glass, which is covered with a uniform coating by the descending metallic vapor. With small objects, such as galvanometer mirrors, a row can be arranged under the wire and treated simultaneously, the operation being completed in about one minute after the necessary vacuum has been obtained. It is claimed that either opaque or semi-transparent mirrors can be produced with equal ease, the thickness of the coating being determined very simply by the time given. Seeing the great difficulty there is in getting really good mirrors by chemical processes, it would seem worth while to give this new method a trial." HENRY A. MORISON. Americanization To the Editor of the SCIENTIFIC AMERICAN: As an interested reader of the SCIENTIFIC AMERICAN for many years, it gave me great pleasure to read in your late number the editorial on "Americanization." In the June 8th number of the "Survey" there is an interesting article on scientific social work. I know your journal is always open-minded; and perhaps you would welcome the suggestion that the SCIENTIFIC AMERICAN and the Survey cooperate to a small extent. It would seem that thp times call for such action, for the mutual good of scientists, engineers and sociologists. The writer is a chemical engineer by profession but has devoted much time and work to labor and social problems. It would seem unnecessary to call your attention to the menace of after the war, a possibility of calamity greater than that of the war itself, and which the sociologist now admits his entire inadequacy to meet alone. If not already too late, the engineer may be able to come to'his rescue. Any step in this direction will be greatly welcomed by the sociologists throughout the country. RALPH P. LOWE. Fitchburg, Mass. Shell Shock Seventy Years Ago To the Editor of THE SCIENTIFIC AMEWCAN: In view of the constant emphasis laid upon "shell shock" as a cause of casualties in modern warfare, it might be interesting to note that the first case brought to public notice occurred in the Mexican War of 1847, at the siege of Vera Cruz. A mortar shell from Fort San Juan fell in one of the batteries shelling the "Merced" quarter, and Captain John R. Vinton, of the Third Artillery was killed. It was noticed that his cap was blown off, but that his skin was nowhere broken, and in the light of modern experience there can be little doubt that he was the first victim of shell shock. As late as 1895 an encyclopaedia mentioned his death as due to the "wind" of the shell, and thought it necessary to add a foot-note saying, "The facts are undoubtedly as stated. Whether death resulted from the "wind," from heart disease, or from other organrc troubles may be an open question." Shell-shock is no longer a mystery, but it is rare that the solution of an "open question" has been so costly of lives. W. F. JENKINS. Fentress, Va. From Warship to Cargo Vessel To the Editor of the SCIENTIFIC AMERICAN: I read with interest the illustrated article in the April 27th issue about the three transformations of the cruiser "Boston." It seems a pity from the sentimental standpoint to change one of Admiral Dewey's warships: into a cargo carrier, but our need of up-to-date battleships and cruisers and men to handle* them dictate otherwise. Also when there is such a need of cargo-carriers, and it was feasible from the financial standpoint to use an old ship like the "Boston" for this purpose, why can't our Government go further along this line? I see from your special naval issue of April, 1898 that the "Boston" has 3,000 tons displacement and that of ou oldest ships there are the "Atlanta," sister ship to the "Boston," "Chicago," "Newark," and "Baltimore," all except the "Atlanta" of greater displacement than the "Boston." These ships are all cruisers and we certainly could spare a few of them (this is a war of torpedo boat destroyers and capital ships), and remodel them into cargo carriers. Then there are the semi-protected cruisers, "Denver," "Cleveland," "Chattanooga," "Des Moines," "Galveston," and "Tacoma" described in your issue of December, 1901. These sister ships each have 3,200 tons displacement, somewhat greater than the "Boston." Your account states these would be better warships if they had 20 knots speed with more suitable protection and guns. Could not these ships also be transformed into cargo carriers thus disposing of unsatisfactory/ warships -for more necessary use? F. E. LOOSLET. Moline, 111.