

IKON AND STEEL. 



541 



Steel drills for shaft sinking, it is also stated, 

 are taking the place of the old iron drills, 

 steeled. 



A trial is now being made of steel stamp 

 heads for crushing ores the fragments of the 

 cast-iron ones heretofore in use, not unfre- 

 quently becoming mixed with the ores, and in 

 this way often causing trouble. 



Mr. Charles Bathoe states that, in India, 

 glaziers never use a diamond to cut glass, but 

 do all their glass-cutting with a hardened steel 

 point. He has himself hardened steel so that 

 it was as brittle as glass, by plunging it at 

 nearly a white heat into iced water. 



Coloring, Bronzing, and Preserving Iron and 

 Steel. Mr. H. A. Bonneville, England, has 

 patented a method of accomplishing the pur- 

 poses indicated, and which consists, in brief, in 

 effecting the following results, namely : First 

 creating at the surface of the iron or steel an 

 adherent coat of peroxide of iron, he then, sec- 

 ondly, under the influence of water at an ele- 

 vated temperature, transforms this into the 

 black oxide, which contains a less proportion 

 of oxygen ; thirdly, he renews the operation 

 until the adherent black coat is of sufficient 

 thickness; fourthly, he immerses the articles 

 in a bath of lukewarm water, for the purpose 

 of removing any acidulated or saline particles 

 that from the previous processes may remain 

 adhering to the coat of oxide ; and, lastly, 

 dresses this coat by rubbing it with olive oil. 



Protection of Iron from Busting. The read- 

 er will find a statement of certain methods that 

 have been proposed or adopted for accomplish- 

 ing the important end here indicated, in the 

 section entitled "Preserving the Bottoms of 

 Armored Vessels," under the head of " NAVY, 

 UNITED STATES," in this CYCLOPAEDIA for the 

 preceding year ; and incidental mention of one 

 or more such methods also, under the head of 

 " CHEMISTEY," in the same volume, and in the 

 present. The object of the process in the sec- 

 tion preceding this, it will be seen, is that of 

 producing (in a mode different from painting) a 

 coat which shall afford a good color as well as 

 protection. 



In two articles appearing in the "Scientific 

 American," of October 31st and November 7th, 

 1863, a summary is given of some of the more 

 important (chiefly English and French) pro- 

 cesses patented or brought into use since the 

 year 1739, but principally since about the year 

 1840, for protecting from oxidation surfaces of 

 iron which may be exposed to the action of 

 salt water, or to rains, or the action of damp 

 air, the earth, &c. Much of the information 

 thus given is condensed from a longer article 

 which had appeared in Mitchell's " Steam Ship- 

 ping Journal ; " and it is made to include (in 

 the article for November Vth) a brief notice of 

 processes for preserving timber. Among the 

 methods of more recent date named for the 

 protection of iron in different situations from 

 rusting, are these : in 1860 that of Mr. M. 

 Allen, for the application of gas-house tar to 



the inside of boilers, and to ships ; that of Mr. 

 E. Smith, for a mixture of pitch, tar, resin, and 

 asafcetida, in turpentine, to the bottoms of ves- 

 sels ; and that of Mr. Gr. Hallet, for a paint 

 composed of oxide of antimony and linseed oil ; 

 and in 1861, that of Mr. John Snider, of this 

 country, for a composition of finely-powdered 

 amorphous graphite with linseed oil and bees- 

 wax, for coating ships' bottoms ; and that of 

 Messrs. Hallet and Stenhouse, for a mixture of 

 native oxides of antimony with red lead, as a 

 paint for iron. 



At a meeting of the Institute of Naval Ar- 

 .chitects, held during the past year in London, 

 Prof. W. J. Hay, of the Naval College at Ports- 

 mouth, described a composition for which he 

 had obtained a patent in 1861, though he had 

 been making trials of it since 1857, and which 

 is said to be very effectual for its purposes. In 

 preparing this, a sub-oxide of copper is roasted 

 until it has absorbed sufficient oxygen to con- 

 vert it into black oxide ; it is then reduced 

 to powder, and boiled in linseed oil, until 

 the mixture assume* a puce color. This mix- 

 ture should be moderately thick or consistent, 

 when applied. The armor-clad frigate War- 

 rior, it was stated, was coated with this paint ; 

 and further, that when this vessel was docked 

 after having been nine months in service, no 

 signs of oxidation were observable in the plat- 

 ing, and the bottom of the vessel was com- 

 paratively clean. 



In the " Jour, of the Society of Arts," No. 

 559, appears an account of a process patented 

 by Prof. J. P. Jouvin, chief medical officer of 

 the French navy, and claiming to be a mode of 

 " preserving iron-plated and other vessels, and 

 metallic articles, from oxidation, and preventing 

 ships' bottoms from fouling," the article ap- 

 pearing also in the " Jour, of the Franklin In- 

 stitute," Dec., 1863, the method itself being 

 said, however, to be essentially a revival of that 

 of zinc protectors patented by Mr. John Ke- 

 vere, in 1830. 



In Jouvin's plan, the inner surface of ships' 

 sides and bottoms, perfectly scoured, are lined 

 with sheets or laminae of zinc, applied directly 

 against the sheet iron, and there held fast 

 between the latter and the frames. The diffi- 

 culty of applying such a lining in ships already 

 afloat, has led to the substitution for these of 

 a double coat of a paint of powdered metallic 

 zinc, applied, after scouring as before, all over 

 from the keel up to a little above the water 

 line: the paint, owing to the fatty matter it 

 contains, being a less decided electric protector 

 than the metal, the area of the protecting sur- 

 face is increased. In case of iron ships in 

 course of construction, both the powdered ziuc 

 and the sheets are applied, the former first 

 upon the frame, &c., when first setup, and also 

 upon the inner skin, beneath the included tim- 

 bers of the hull. Holes are left in the plates 

 for the rivets to be put in hot ; and when the 

 riveting is completed, the spaces including the 

 rivet-heads are covered with the paint. The 



