280 ANNUAL EEPOET SMITHSONIAN INSTITUTION^ 1912. 



tion the pressure upon the whig is of course changed, and then agam, 

 but for a different reason, the movable mass undergoes a displace- 

 ment. In both cases the change in the position of the mass is used 

 to actuate, by means of a compressed-air auxiliary motor, the eleva- 

 tion rudder of the aeroplane. 



The idea of thus combinmg in one apparatus the mfluence of an 

 acceleration with that of a velocity is not so new as the inventor 

 supposed, for the regulator of a steam engine called the "American 

 Regulator" applies the same idea.^ But the merit due to Doutre is 

 because of his idea in using the device for the safety of aviation, and 

 I should add that the experiments so far made shov/ its feasibility. 

 It remains to see how it will work after longer and more varied trials. 



Delaporte is the inventor of a contrivance called by him a movable 

 aero propeller and consisting of a device caiTying a motor and an 

 air propeller. It is necessary only to install it upon a boat in order 

 to make the latter automobile. Delaporte sees m his invention the 

 solution of the important problem of the navigation of canals. A 

 demonstration of the aero propeller was made at Toulouse September, 

 1911. It was found that a flat-bottomed boat provided with a 

 3-horsepower aero propeller could be easily managed and would tow 

 up to 8 boatloads of 40 people each. 



V. CONGRESS AT DUSSELDORF. 



In 1910 there was held at Dusseldorf a Congres de Mecanique, 

 where a speciality was made of the application of mechanics to mming 

 and metallurgy. The following are a few abstracts from the pro- 

 ceedings of that congress : 



■ Electricity is more and more used m mines for drilling, for hoisting, 

 for ventilating and exhaust pumps, and for extracting machines. 

 In the metallurgical laboratory it is frequently used for the forges 

 and the rolling machines. It serves further for the heating of the 

 furnaces and for welding. One paper treated of the transportation 

 by aerial cables which exceed 30 kilometers in length. 



Another memoir gives the history of the development of the blower 

 and compression in German mmes. Blowers are now made capable 

 of blowing in an hour 16,000 cubic meters of air at a pressure of 300 

 millimeters of water. The turbine compressor, invented by Rateau, 

 is now widely distributed. These machines are often driven by low- 

 pressure turbines to which I referred in the Review for 1909 and 

 whose invention was also due to Rateau. The latter at the Dussel- 

 dorf Congress j)resented an important communication upon the 

 present status of low-pressure turbines. Their steam is furnished 

 by an accumulator receiving the steam escaping from a certain 

 number of ordinary engines. The low-pressure turbine is so built 



> See my article on Regulators in 1900, Revue g6n6rale des Sciences, 1901, pp. 125 et seq. 



