June 29, 1900.] 



SCIENCE. 



1031 



NOTES ON ENGINEERING. 

 ' CHILLED ' CAST lEON FORTS. 



Documents laid before the Board of Fortifi- 

 cation and Ordnance of the United States Army, 

 recently, contain some interesting information 

 regarding the applicability of one of those 

 materials which this country has always pro- 

 duced in highest perfection, in the construction 

 of coast-defences. This country, alone, em- 

 ploys chilled cast iron to the exclusion, practi- 

 cally, of all other materials in car-wheel con- 

 struction and certain brands of domestic irons 

 possess a very extraordinary combination of 

 strength, toughness, and capacity for taking on, 

 by 'chilling,' a hardness exceeding that of tool- 

 steel. Our ordnance east irons, in earlier days, 

 were of rare quality and our irons and steels 

 generally are unexcelled. 



For some years past, the Grusonwerk of 

 Magdeburg-Buckau has been employing chilled 

 cast iron in the construction of shields and tur- 

 rets in the coast-defence systems of European 

 countries, practically after the plan of the 

 American inventor, Timby, of a half-century 

 ago and of his licensee, John Ericsson, who used 

 the device on the 'monitors.' The ' Endicott 

 Board,' represented by Captain Bixby, U. S. A., 

 investigated this matter, in 1865, with the result 

 that the system was recommended and the erec- 

 tion of 22 such turrets was advised for defense 

 of our principal harbors. 



It was found that some forty turrets had been 

 built for European governments and that prob- 

 ably many others, the location of which had 

 been carefully concealed, were in existence. In 

 the famous trial at Spezzia, an Italian turret 

 was attacked by the shot of an Armstrong 100- 

 ton, 16.93-inch, gun at 150 yards, the projectile 

 weighing one ton, and withstood three such 

 shots, each impact measuring 47,566 foot-tons. 

 They have since been erected and accepted by 

 a number of the European governments for de- 

 fence of particularly important points. Ger- 

 many has ten or a dozen. 



In this countrj', notwithstanding our special 

 advantage in quality of iron suited to this pur- 

 pose, the general indifference of Congress and 

 the people respecting coast-defence up to the 

 outbreak of our recent war prevented any action 

 being taken toward introduction of this later 



Timby turret, the Gruson chilled iron construc- 

 tion. In 1898, however, in the midst of the 

 excitement and anxiety awakened by the 

 rumors of a possible descent of the enemy upon 

 our coasts, Mr. P. H. Griflfin, of Buffalo, a well- 

 known and expert manufacturer of chilled iron 

 wheels, aud other constructions, privately ne- 

 gotiated with the Krupps, who had by this time 

 assumed control of the Gruson invention, and 

 secured the right to build in this country and 

 was given possession of the various special secret 

 and expert methods which had made the Gru- 

 sonwerk successful. A company was formed 

 in the United States, and it is, as we are in- 

 formed, now established in new works at Ches- 

 ter, Pennsylvania. This remarkable and im- 

 portant manufacture is thus finally brought into 

 a country in which it is known that the finest 

 material in the world is available for its i5ur- 

 poses. * 



The satisfactory chilling of cast iron to a 

 depth of a fraction of an inch and on the surfaces 

 of small masses, like car-wheels, has not been 

 always found an easy matter ; the production of 

 the chill required for ordnance purposes on the 

 surfaces of masses weighing from four to six 

 millions of pounds involves, undoubtedly, some 

 peculiar and difiicult manipulations. Should it 

 prove as successful, however, as with our car- 

 wheels, another important addition will be 

 made to the list of benefits conferred, by the 

 metallurgical chemist and the foundryman 

 together, upon our industrial system. This 

 constitutes one of the most remarkable scientific 

 achievements of the time. 



THE 'AIR-SPLITTING TRAIN.' 



The daily press of recent dates has been sup- 

 plied from Baltimore with interesting and im- 

 pressive accounts of the repetition of the Bes- 

 semer experiment with what is now denominated 

 the ' air-splitting train,' a train which is given, 

 as far as practicable, the form of a cigar in its 

 outer shape and which thus evades to some ex- 

 tent the head-resistance of the air and the 

 friction of irregular surfaces on the side of the 

 train and at its junctions between adjacent cars. 



* See paper by Mr. T. Gniltord Smith, ' Gruson 

 Rotating Turret.' Trans. Am. Inst. Min. Eng., Feb. 

 1900. 



