542 



IROK AND STEEL. 



protecting bands of zinc, properly fixed from 

 the keel up to the water line, need cover only 

 from two thirds at maximum, to one tenth at 

 minimum, of the surface to be protected, the 

 intervals being covered with the zinc paint. In 

 iron-plated vessels, the paint is applied upon 

 the wooden hull, or the sheets between it and 

 the plates, the latter first being well painted 

 also on the inner side. 



To protect the exterior of the hull under 

 water from the deposit of marine shells and 

 plants, Prof. Jouvin applies a mixture of tur- 

 peth mineral (sub-sulphate of mercury), Prus- 

 sian blue, and red lead, in boiled linseed oil, 

 from the contact of the two first-named of 

 which salts with the alkaline chlorides of sea- 

 water he declares the powerfully poisonous 

 cyanide of mercury to result. This paint is 

 applied over two previous coatings of that of 

 metallic zinc v the hull having been first well 

 scoured. To preserve sheet-iron tanks, marine 

 boilers, steam engines, and other similar con- 

 structions from oxidation, the inventor either 

 applies on them externally zinc sheets, or coats 

 them with a double layer of the zinc paint. 

 To preserve the parts of cables and chains, 

 situated within wells, and liable to rapid oxida- 

 tion, a band of zinc is fastened on each ring or 

 link by screws. The paint also may be applied 

 to iron articles in general, as a substitute for red 

 paint, and wherever the latter is now used. 



A mode of applying copper sheathing upon 

 iron or iron-clad ships, which has been men- 

 tioned, is that of planking with wood to a little 

 above the water line, countersinking the bolt- 

 heads, covering the whole with a coating of 

 asphalt and then with felt, to secure electrical 

 insulation, and then sheathing over all with 

 copper. Copper sheathing which fouls may 

 be protected by painting with Jouvin's poison- 

 ous compound, above described. 



A new and peculiar method of protecting 

 iron ships has lately been patented in England. 

 The covering applied on the metal, and which 

 is known as " Brown's vitreous sheathing," 

 consists of a coating of glass fused with small 

 plates of iron, the whole intended perfectly to 

 prevent the contact of sea- water with the iron, 

 and at the same time to possess a certain de- 

 gree of flexibility. 



Mr. F. Grace Calvert recommends that, 

 for the preservation of the material of iron- 

 plated and other ships, ,all the iron used in 

 shipbuilding should be galvanized. In some 

 experiments performed by him in the years 

 1862 and '63, in the way of immersing in dis- 

 tilled and also in sea water, pieces of wood, 

 some coated with iron only, and others with 

 galvanized iron, the corrosion and loss of the 

 galvanized iron plates in both the soft and the 

 salt water was very small compared with that 

 affecting those of ungalvanized iron. He be- 

 lieves that the galvanizing of the bolts and 

 other iron used about wooden ships will great- 

 ly lessen the decay of the wood itself, with 

 which the iron is in contact. And in order to 



ITALY. 



determine the force of adhesion of the zinc 

 coat applied in galvanizing to iron, he caused 

 large galvanized bolts to be driven with a 

 sledge hammer into solid blocks of oak, and 

 also screws to be forced into similar blocks : 

 upon then opening the blocks so as to release 

 the bolts and screws, the latter were found to 

 be not in the slightest degree uncoated. 



In course of a discussion, during the summer 

 of 1863, before the Society of Arts, London, 

 Mr. C. F. Varley said, in reference to galvanized 

 iron, that all attempts to use this for roofs in 

 large towns have failed, from the circumstance 

 that some component of the smoke attacks and 

 corrodes the galvanized metal; while tinned 

 iron does not resist the action of smoke so 

 well even as zinc. All the experiments he had 

 seen for coppering iron, failed, unless done in a 

 manner too expensive for general use. He 

 thought that what is required is a covering of 

 iron with lead, or lead and antimony, so as to 

 combine the stiffness and cheapness of iroti 

 with the durability of lead. Col. T. P. Schaff- 

 ner stated that in some countries it is practica- 

 ble to cover houses with tinned iron ; and that 

 in America this is largely used instead of 

 lead. In St. Petersburg and Moscow, iron 

 is mostly used, but it requires frequent paint- 

 ing. In the telegraph service, he has tried 

 many experiments for the preservation of the 

 wires, as by galvanizing, and the use of linseed 

 and other oils ; and though he had boiled the 

 wires in linseed oil, with good results, they 

 would still decay. Mr. Yarley, sen., stated 

 that if iron is heated and passed through oil, 

 the pores become filled, and the metal lasts a 

 long time. Mr. Kevely mentioned that iron 

 heated and covered with asphaltum had resist- 

 ed a moist atmosphere for fifteen years. He 

 had found the natural asphaltum best for this 

 purpose, and had not succeeded so well with 

 the liquid bitumens. In case of all other pro- 

 tecting materials, he had found that rusting 

 would begin underneath them. Mr. John 

 Braithwaite stated that the means of prevent- 

 ing oxidation adopted by his father, and fol- 

 lowed by himself during the past fifty years, 

 was that of painting the iron with red lead. 

 "White lead is of no value for such purpose. He 

 had inspected a well, 200 ft. deep, in which 

 were rods connected with an engine, and placed 

 there by himself forty-five years ago : these 

 rods were at the first painted with pure red 

 lead, and upon taking them up after the lapse 

 of that time, he found their weight precisely 

 the same as when they were put down. 



ITALY, a kingdom in Southern Italy, which 

 now comprises the whole territory inhabited by 

 Italians, with the exceptions of the Papal 8; 

 which form an independent State, Venetia, 

 which belongs to Austria, Corsica, which be- 

 longs to France, and the canton of Tessin, 

 which belongs to Switzerland. 



The king of Italy is Victor Emanuel II., born 

 March 14th, 1820, the eldest son of King Charles 

 Albert, of Sardinia. He succeeded to the 







