Compulsory Licenses and Working Clause To the Editor of the 8CIENTIFIC AMERICAN: Samuel S. Dale, in his letter published in your issue of April 24th, does little to impair the argument of Commissioner of Patents Ewing against compulsory license and compulsory working of patents. Mr. Dale adopts a curious course of reasoning: The British working clause of 1907, he declares, caused an immediate development of manufacturing which had previously been conducted in foreign countries. But this is not the model, Mr. Dale hastens to assure us, which we ought to follow. Advocates of a working clause,' ' he declares, are not urging the adoption of the provisions of the British patent system. What then are they advocating? Mr. Dale replies: They are advocating the adoption of an effective working clause in the United States law. But what the terms of this shall be, in what way it shall improve upon the British law and specifically just what it is, Mr. Dale does not state. There is always a sure, quick and infallible test to apply to enthusiasts with legislative proposals; and that is to compel them to phrase in specific language just the law they want. If their ideas have merit, they readily stand the test. If they lack merit, the process of trying to satisfy the test is always educative to the community and sometimes especially educative to the enthusiast. Perhaps, if Mr. Dale will acquaint himself with the literature which has already accumulated upon this subject and read all the hearings which have been held during the past few years by the House Patent Committee, he would see the answer not only to all the questions which he now raises, but to many other questions which much more industrious students of the problem have raised. Mr. Dale's quotation from the recent speech of the president of the British Board of Trade is strangely misdescribed by Mr. Dale as showing that the British working clause will work in the future. In fact, the passage quoted is from the statement of the British government regarding its policy in respect of German patents which, like other German property coming within the control of the British authorities upon the outbreak of the war, have been laid hold of by the government to abide the termination of hostilities. Mr. Dale's naive assumption that what Great Britain is now doing to the property of the enemies with whom she is at war can afford a wholesome precedent for what the United States should do with the property of foreigners with whom we are not at war is, perhaps, the strangest delusion that the whole compulsory license dementia has yet produced. What relation Mr. Dale bears to the textile industry, for which he presumes to speak, is not disclosed in his letter. To the credit of this industry it should be said that instead of seeking relief in the will-o'-the-wisp of compulsory license or compulsory working of patents, it is concentrating its attention upon tariff protection . against dumping which is barely alluded to by Mr. Dale as one of the other factors involved in this problem. The hearings before the House Patent Committee last winter at which representatives of the textile industries appeared, and the recent report of the Secretary of Commerce on the dyestuff situation, seem to indicate that the more responsible leaders of opinion upon this subject are laboring under no such misconceptions as oppress Mr. Dale. J. N. V. New York, N. The Superheated Steam Unit To the Editor of the Scientific Amebican : In the issue of March 27th, 1915, of the Scientific American, I think a mistake has been made on page 290. See third column, test No. 5. The sentence which begins in the twenty-second line from the top is as follows: "The double superheat feature appears also in this locomobile, and as tested by the exposition judges it gave 8.70 pounds of coal and 1.02 pounds of steam per brake horse-power on a superheat of 649 deg. Fahr." This statement might be very misleading to the uninitiated. Mr. Miller's article is both interesting and instructive, but it ;;eems certain to me that the words coal and steam1 ' have been transposed. I have accepted the information with this assumption. Jersey City, N. J. A. Ij. Thurston, M.E., E.E. The Roosevelt, Peary's Arctic ship, has been acquired by the U. S. Bureau of Fisheries and is to be used in connection with the work of that bureau in Alaskan waters. She was built expressly for Arctic service in 1905.