Trans. N. V. Ac. Set. 66 Fed. i8, 



Where the strands separate on entering the anchorages they were 

 completely enclosed in paraffine, as it would hereafter be difficult to 

 paint them at those points. 



As to the ways in which the wires were attacked, they were three: 

 First : As if acted upon by an acid, showing clearly the so-called 

 "fibre" of the wire. Second: A roundish, black-looking lump of 

 hard scale would be found, which, when knocked off, would leave a 

 deep pit in the wire. This scale was largely composed of sulphur, 

 and resembled a sulphide of iron. Third: In a few cases the " skin " 

 of the wire was corroded through in a narrow slit, and then the whole 

 interior eaten out, much like the decay of wood at the heart. This 

 was not often seen, but might easily have been overlooked. 



Professor W. P. Trowbridge inquired whether the wire had been 

 examined at any portion of the catenary, and also whether there was 

 anything known in reference to the lifetime of the bridge ; and sug- 

 gested that a single wire broken or rusted would make a weak point in 

 the cable. 



Mr. COLLINGWOOD replied that the damage to the wires did not 

 extend more than two feet from the anchorages in any case. The 

 cables had been examined at the points where they passed over the 

 towers, and at several intermediate points, and (with the exception of 

 damage to the wrappings, which was easily repaired) the wires, on 

 which the strength of the bridge depends, were intact. Experi- 

 ments for tensile strength and stretch were made on both old and new 

 wire, using an accurate gauge, registering to the thutto of a 

 foot, and the stretch, reduction of area at point of rupture, and 

 strength were practically identical. The paint was found defective at 

 many points on the cables, and, to insure a perfect covering, the old 

 paint was shaved off and two heavy coats of new put on. There is 

 no reason why the bridge should not last a thousand years, if properly 

 cared for in the future. 



The President remarked that the atmosphere in Pittsburg was 

 charged with sulphuric acid, and that this acid-water was certain to 

 make its way into the cable through any crevice, and soon destroy 

 the iron. No mere decomposition of any hydrocarbon could yield so 

 large a quantity of water as that found. The dark product of the 

 decomposition of the wire was probably the simple sulphide of 

 iron. 



The subject was further discussed by Professor Trowbridge. 



The President announced the death of Professor Arnold 

 GuYOT on February 8th, and briefly sketched his character and the 

 principal incidents of his life. He was born in Neufchatel, in 



