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farming, mining and manufacturing interests, even in a year of depression and drastic price declines such as 1931, is indicated by the value of our domestic exports which amounted to $2,- 377,981,786, every state and territory partici- pating. Germany, second in rank of exports, showed a value of $2,192,350,000, while the United Kingdom in third place, including re- exports, reached a total of $2,069,823,000 in value. All other countries showed much smaller totals, France, in fourth place, attaining a value of only $1,192,516. Of what significance is this tremendous ex- port trade to American labor? The secretary’s answer is that more than 1,400,000 workers di- rectly engaged in producing goods for export in 1931 received more than $1,500,000,000 in wages. Probably an equal additional number of workers were employed indirectly in service activities and in supplying the needs of those engaged directly. What could more forcibly bring home to every individual, wherever he lives, the need of a merchant marine of our own so that this great trade and its future growth will not depend en- tirely on the convenience and the will of for- eign carriers. We do not need to, do not want to, and do not expect to carry more than a fair proportion of this trade in ships flying the Amer- ican flag. But what an utterly indefensible pol- icy it would be to depend solely on foreign car- riers for the delivery of this vast volume of goods. As the world recovers from existing con- ditions this volume will be expanded to a much higher level and we must be prepared with mer- chant ships of our own to take our rightful place in world trade. New Metals Used in Shipbuilding HIPBUILDING, like any other industry, S must prepare to discard custom, to adopt new methods and materials as they are developed and proven of value. In this con- nection W. E. Blewett, Jr. of the Newport News Shipbuilding & Dry Dock Co. recently presented an interesting paper on New Metals Used in Shipbuilding, at a meeting in New York of the American Society for Steel Treating. The ship- builder is prone, to hold to the materials which he knows from practice to be reliable. Undue risks should not be taken. Nevertheless new materials are constantly finding their way into shipbuilding. The author states that the most important materials used aboard ship are the high tensile steels, alloy and heat treated. Of these two the alloy steels as a group is more expensive and the one for which best results may be expected. No less than seven alloy steels have recently been experimented with for ship construction. In deciding which steel will give the best re- sults, numerous tests should be made of steels which have been commercially prepared. Since various rollings of the same steel often give diversified results, the final answer as to the most suitable steel can only be obtained after practical application. It happens that by the time an answer is obtained other steels are of- fered With the claim of better characteristics. The author has tabulated chemical and impor- tant physical properties of the seven high elas- tic steels on which experiments were recently made. Tests were also made on the workability of the steels in respect to punching and the results noted. Other practical experiments include joggling, shearing and flanging and although no loads were measured it was apparent that Specimens could be worked statisfactorily, though he pointed out that it is likely that somewhat more hot working will have to be done than with mild steel. Experiments were carried out on welding and it was found that the strength of the weld metal remains fairly constant with an average of about 67,000 pounds per square inch. This shows that a good bond was made between the deposited metals and the plates. It was pointed out that in addition to struc- tural steel there are many other steels used in the construction of a ship, including large and small hull forgings, propeller line shafts, rotor shafts, crankshafts, etc. Stainless steels are rapidly finding new applications in marine work and are now being used for turbine blad- ings, valve disks, valve stems, etc. Stainless steel is also useful in galley equipment and for fittings and ornamental work in passenger quarters. Materials for rivets going into the ship’s hull, especially the under water part, are always a source of argument, some preferring iron, oth- ers alloy, and still others plain mild steel. In determining the best material to use the serv- ice of the ship should be considered. Proper heating and driving of shell rivets are also im- portant for good rivet material can be ruined by improper use. An important group of ma- terials in ship construction is the nonferrous metals and their alloys. In a ship of 30,000 tons displacement approximately 350 tons of nonferrous metals are used. An interesting phenomenon in connection with copper pipe was touched upon. Pipe of 10 MARINE Review—May, 1932