338 Historical 



length of the spinal cord. Baumgarten found in this focus abundant 

 cells of the neuroglia attacked by fatty degeneration. 



The same facts were told by the chief engineer of bridges and 

 highways, Malezieux, 32 in his fine report on the public works of 

 the United States of America in 1870. He copies verbatim (p. 91-93) 

 the passage from the report of the engineer Eads which we quoted 

 above. 



M. Malezieux has also given details about the foundation of the 

 bridge which was to connect New York to Brooklyn. At the time 

 of his visit, they were only at the beginning of this work. But the 

 plans were gigantic; the foundation caisson was 52.46 meters long 

 by 31.11 meters wide, that is, more than 16 ares in area. 



In the second Memoir, 33 M. Malezieux gives the depth actually 

 reached. The Brooklyn pier had a foundation 15 meters deep; the 

 New York pier, 24 meters. 



For the latter, steam-heating was installed in each of the air- 

 locks, so as to prevent the chill produced by the sudden escape 

 of the compressed air (p. 385.) 



As to the physiological effects, M. Malezieux states: 



That he has little to add to what he reported previously about 

 the Saint Louis bridge. M. Roebling (that is the engineer and con- 

 structor), however, notes this fact, that the action of the lungs is 

 changed involuntarily in compressed air; the number of times one 

 breathes in a given time is reduced 30 to 50 per cent; which would 

 indicate that the organism reacts against the introduction of oxygen 

 in a proportion two or three times greater than in normal atmosphere. 



The natural conclusion to be drawn from this observation is the 

 one which M. Eads had made at Saint Louis; to shorten the duration 

 of work in compressed air as the pressure increases. (P. 395.) 



I shall quote in conclusion some information which I owe to 

 the kindness of the managers of a great industrial company, which 

 does a great deal of work on the foundations of bridges with the 

 use of compressed air. These documents refer to works executed 

 very recently outside France; a discretion the motives of which 

 everyone will understand prevents me from giving more definitely 

 the details of date and place. 



First, here are general specifications about the manner in which 

 the works were carried on, and which resulted in the accidents; 

 these specifications come from the superintendent of the job him- 

 self: 



1. At a depth of 20 to 22 meters, the shifts still lasted 8 hours, 

 and our men were not too tired, none of them felt any ill effects 

 from the pressure, they were merely inconvenienced by the evil 

 odor of the mud and by the hot air, which, however, we took care to 



