Panama Canal Looks in War. To the Editor of the SCIENTIFIC AMERICAN: One of the strongest arguments made for the United States undertaking the construction of the Panama Canal is that it will be invaluable to us in case of war with a foreign nation, in that it will enable our warships to pass quickly from one ocean to the other. But for this very reason, the first attempt on the part Of any nation going to war with us will probably be to close the canal and thus divide our naval forces. Japan could easily whip us could she attack our Atlantic and Pacific fleets one at a time and prevent them from uniting; and so could Germany or France or Great Britain. And how easy it would be to do this if all that one of these powers had to do, in order to put the canal out of commission for months, were to hire the captain of some old tramp steamer to smash through one of the gates at the locks, drop a few sticks of dynamite overboard, or scuttle the ship at some narrow point. No amount of neutralizing of the canal and international treaties could prevent a little "accident" like this; and it could be far more easily planned and executed than was the little "accident" to the "Maine" in Havana harbor; and the results would probably be far more disastrous to us. In this case, as in the other, it would probably be our first intimation that war was seriously contemplated by the enemy. Such a state of affairs should not only be made unlikely, but it should be made absolutely impossible. There should be a sufficient number of gates and locks, and they should be so arranged with reference to each other, that the crippling of one could by no means destroy the others or cripple the canal as a whole. Wrecking apparatus should be provided, too, so that the sinking of a ship could not block the canal for more than a day or two at the most. These precautions, small though they may seem, may mean the difference, some day, between a glorious victory, on the one hand, and, on the other, defeat, the destruction of our navy, the loss of our insular possessions and a heavy tribute. CHARLES S. ADAMS. Warren, Ohio. Aeronautical Notes. The latest record for duration of flight by an airship is that made by the German military airship of Major Gross, the "Bazenach," which on October 28 last was in the air 8 hours and 10 minutes, during which time it made the trip from Berlin to Brandenburg and return, a distance of 120 kilometers (75 miles). This flight, while of the longest duration, is not the longest as far as distance is concerned, as previously, on September 30, the Zeppelin airship made a flight estimated at 340 kilometers (211*4 miles) in length, during the 7 hours which it was in the air. The best previous record for duration of flight is that of the French dirigible the "Lebaudy," which, on July 6, 1905, was in the air for 3 hours and 21 minutes, during which time it covered a distance of 93 kilometers (57% miles). On November 23, a week before it was lost, the French dirigible "La Patrie" made a flight of 146% miles from Paris to Verdun in 7 hours and 5 minutes at an average speed of about 21 miles an hour. The weather conditions were not good, and wind, rain, and fog were encountered. The officers in charge of the airship expected to descend at Chalons to obtain fresh supplies of gas and fuel; but this was found unnecessary, and the trip was made without a stop. Only 55 pounds of ballast was used, while the fuel consumption was but 37 gallons of gasoline, or less than half the quantity carried. Count Zeppelin has started the construction of a new airship which he is building for the German government. The dimensions of this new airship are given as follows: Length, 130 meters (426% feet); diameter, 12 meters (39 1/3 feet); horse-power, 240, consisting of two Daimler motors of 120 horse-power each, which will be used instead of the two 85-horse-power motors with which the present airship is equipped. The new airship is being constructed in a shed mounted on floats at Manzell on Lake Constance. It is the fourth airship that Count Zeppelin has built. An interesting line of aeronautical experiments were conducted recently by Mr. G. Coleman Brown, of Dallas, Texas, at the "balloon farm" of Carl E. Myers, Frankfort, N. Y., which is an aeronautical experiment station. Here was successfully tested a new aeroplane principle for attaining mechanical flight. This is a heavier-than-air machine based on the aeroplane system. Hydrogen gas is used in connection, but for an entirely new purpose, for which gas was never before employed. The tests were successful in establishing the principle sought, and practical application will later be made. The British War Department has under construction a second dirigible balloon, which will have a total capacity of 64,000 cubic feet and a diameter of 42 feet. The lifting capacity, which is 1,400 pounds more than that of the "Nulli Secundus," will giye it a lifting power of 4,800 pounds. In calm weather it is expected that a speed of 40 miles an hour will be obtained, as the airship will be fitted with a 100-horse-power engine. It is expected to carry six passengers, instead of three, in this new air craft. Aeronautics in Europe. BY THE PARIS CORRESPONDENT OF THE SCIENTIFIC AMERICAN. Somewhat of a sensation was caused at the recent banquet of the Aero Club of the United Kingdom at the Savoy Hotel, London, by the announcement that Senator Henri Deutsch, vice-president of the French Aero Club, had the intention of trying to sail from France to England. M. Deutsch, who was present on this occasion, made a speech in which he dwelt upon the advantages of aerial navigation, not indeed for war, as some wished, but, on the contrary, for advancing civilization. After this, President Richard Wallace of the British Aero Club announced officially that he had obtained from Senator Deutsch the promise to make a flight from France to England on board his airship "Ville de Paris." Mr. Wallace stated subsequently that the trial would take place as soon as a good shed could be secured for the airship, and that he would see whether the military balloon shed of Aldershot could be used for the purpose. He added that the arrival of a French airship in England would be an event of great international importance. Senator Deutsch stated to our Paris correspondent that he would attempt the voyage as soon as the question of garage for the airship was solved. He would choose the most favorable weather for making the start. After crossing the channel, he hoped to arrive at Aldershot, after sailing over London. The-promoters of the aeronautic exposition of Turin wish to give special importance to the show, and to this end they propose to establish two international Grands Prix for aerial navigation. The first prize of $50,000 will be awarded for airships, and the second prize of $20,000 for heavier-than-air apparatus. It appears that the organizers stipulate that the winning apparatus is to be turned over to the Italian government after being placed on exhibition at the show. After hearing of the project King Victor Emmanuel wished to show the great interest which he is taking in the question, both as to the progress of science and the application to military affairs, and accordingly he decided to award a royal cup, which will be competed for during the next international airship contests. On the other hand, it is stated that Lord North-cliff has just established a prize in the name of the London Daily Mail of $500 for an aeroplane which will cover a flight of half a mile, or a quarter of a mile each way, remarking that M. Farman could now easily win this prize. The interest is increasing in Great Britain, and we hear that Mr. Patrick Alexander recently made a wager with Mr. Griffith Brewer of $2,500 that he will accomplish a flight during the year following November 5 of one mile in a closed circuit. In Russia the subject of aeroplanes has been occupy-ir 2: different inventors, and one of the first of these to make its appearance in the field is the new military aeroplane which has been designed according to the system of Capt. Schabsky. It is expected that a speed of 12 meters (40 feet) per second will be reached with this apparatus. Aeroplanes are very active at Paris. Santos Dumont is continuing his experiments at the Bagatelle grounds and is making short flights with his new machine. He has already succeeded in winning the 150-meter Aero Club prize, and he soon expects to make a longer flight. It took him some time to get his machine in good condition, owing to its novelty, but he is now contented with the results. He modified it since our last account by replacing the single high-speed propeller with two propellers of larger diameter, which are mounted side by side upon the flyer and run at a reduced speed. Henri Farman has been profiting by the enforced interval of rest due to the rainy weather by overhauling his aeroplane and putting it in good shape after its recent hard flights. Since then he has been making several good flights on the Issy grounds, and he soon expects to make another official trial for the Deutsch-Archdeacon prize. He is to modify his arrangement of the carbureter again before doing so; it is now placed higher up, and this he found to be much better for giving a good gasoline feed. The Antoinette motor has been now fitted with a magneto and it will operate a new propeller. M. Farman also found that he could lighten the apparatus at least 40 pounds, which is an advantage, and he will now be in better shape than ever. As to M. Bleriot's new aeroplane, he is now trying it at the Issy grounds. Not long since he made the first test by rolling on the ground with his 50-horse-power Antoinette motor, and found that the framework was in good shape. This he reinforced, as before he saw that it was not strong enough. After this he made a long flight at a very high speed, and this he estimated to be not less than 50 miles an hour. His motor and propellers allow him to travel at a comfortable speed. Coming down to the ground, he somewhat damaged his carrying wheel, but this was not very serious and can easily be set right. With such a speed he will have what is needed for going around curves. However, he requires more practice with it in order to be able to operate it successfully. On the same grounds, M. Bischoff is carrying out his tests of his aeroplane. He uses an improved wood propeller made by the constructor Chauvire. During the recent attempts, he traveled over the ground, but unfortunately ran into a tree at the side of the grounds and somewhat injured his machine, which ran head down, and the rear became entangled in the branches of the tree. He will soon have the machine repaired, however. The Zens brothers are building a new aeroplane at Paris, and these inventors, who are well known in aeronautic circles, will soon have their apparatus finished for trial. It has two superposed plane surfaces with a rudder placed in front, and is fitted with a 50-horse-power Antoinette motor. M. Vuia, who made an aeroplane some time ago, and seems to be the first who adopted the method of using a rolling carriage so as to rise up from the ground, has been at work for some time upon his aeroplane, and has modified it considerably. Abandoning his carbonic acid motor, he uses an 8-cylinder gasoline motor giving 25 horsepower, and expects to begin the flights with it in the near future. As to M. Esnault-Pelterie, he has discontinued his experiments near Paris in order to build a new aeroplane which will be modified according to the results of his previous work. He may construct several different types of apparatus, fitted with 30 and 60 horse-power motors. The Current Supplement. The increased weights of railroad locomotives and cars has created a demand for heavier cranes for breakdown purposes. The English correspondent of the SCIENTIFIC AMERICAN describes a British articulated breakdown crane which meets this new demand. "Panama a Half Century Ago" is the title of an article based upon an old diary which was kept by a forty-niner. As one of the most important factors in the construction of a steam vessel is the riveting and especially so in vessels of such dimensions and power as the "Mauretania" and her sister vessel "Lusi-tania"it was decided to resort to hydraulic riveting to a much larger extent than usual in their construction. A most excellent article by E. W. de Rusett describes the hydraulic riveting machines which were used, and the character of the four million rivets that hold the plates together. The problem of how to protect structures from dampness is one whose solution was attempted even in the remote ages of antiquity. In an article entitled "Scientific Waterproofing" modern methods are described. The seventh installment of Prof. Watson's "Elements of Electrical Engineering" is published. The subject discussed is "Principles of Direct-Current Motors." "For certain branches of suburban railroad traffic the Prussian State Railroad Department has introduced an accumulator-propelled passenger car. This new vehicle is thoroughly described in an illustrated article. The denatured alcohol situation is summarized. A new method of reducing atmospheric nitrogen is described. Cornelia Kennedy writes on "Wheat through Mill to Market." The Paris correspondent of the SCIENTIFIC AMERICAN presents an interesting account of some automobile novelties which were exhibited at the recent Automobile Shows in Paris. To Our Subscribers. We are at the close of another yearthe sixty-second of the SCIENTIFIC AMERICAN'S life. Since the subscription of many a subscriber expires, it will not be amiss to call attention to the fact that the sending of the paper will be discontinued if the subscription be not renewed. In order to avoid any interruption in the receipt of the paper, subscriptions should be renewed before the publication of the first issue of the new year. To those who are not familiar with the SUPPLEMENT, a word may not be out of place. The SUPPLEMENT contains articles too long for insertion in the SCIENTIFIC AMERICAN, as well as translations from foreign periodicals, the information contained in which would otherwise be inaccessible. By taking the SCIENTIFIC AMERICAN and SUPPLEMENT the subscriber receives the benefit of a reduction in the subscription price. In a review of the metal trade, the Torg. Prom. Gazeta observes that the importation of aluminium into Russia fell to 7,000 poods in the first half of this year, against 24,000 poods in the corresponding period of 1906. The tendency on the part of platinum, according to advices from the Urals, says the same authority, is distinctly downward. The exportation of this metal, according to customs returns, has fallen from the level of 156 poods in 1906the first six monthsto 90 poods in the first six months of this year (1 pood=36.07 lbs.),.