FREE BOOKS

Author's List




PREV.   NEXT  
|<   84   85   86   87   88   89   90   91   92   93   94   95   96   97   98   99   100   >>  
The want of adhesion between the deposited coating and the article need not be feared if cleanliness be attended to and the article, while in the bath, be not touched by the hands. The bath should be neutral, or nearly so, slightly acid rather than alkaline. It is obvious that, as such a liquid has no detergent action on a soiled surface, scrupulous care must be taken in scouring and rinsing. Boiling alkaline solutions and a free use of powdered pumice and the scrubbing brush must on no account be neglected. A few words on the construction of the tanks. A stout wood box, which need not be water-tight, is lined with sheet lead, the joints being blown, _not soldered_. An inner casing of wood which projects a few inches above the lead lining is necessary in order to avoid any chance of "short circuiting" or damage to the lead from the accidental falling of anodes or any article which might cut the lead. It is by no means a necessity that the lining should be such as to prevent the liquid getting to the lead. On a future occasion I hope to supplement this paper with the analysis of the double sulphates used, and an account of the behavior of electrolytically prepared crucibles and dishes as compared with those now in the market.--_Chem. News_. * * * * * CHILLED CAST IRON. At a recent meeting of the engineering section of the Bristol Naturalists' Society a paper on "Chilled Iron" was read by Mr. Morgans, of which we give an abstract. Among the descriptions of chilled castings in common use the author instanced the following: Sheet, corn milling, and sugar rolls; tilt hammer anvils and bits, plowshares, "brasses" and bushes, cart-wheel boxes, serrated cones and cups for grinding mills, railway and tramway wheels and crossings, artillery shot and bolts, stone-breaker jaws, circular cutters, etc. Mr. Morgans then spoke of the high reputation of sheet mill rolls and wheel axle boxes made in Bristol. Of the latter in combination with wrought iron wheels and steeled axles, the local wagon works company are exporting large numbers. With respect to the strength and fatigue resistance of chilled castings, details were given of some impact tests made in July, 1864, at Pontypool, in the presence of Captain Palliser, upon some of his chilled bolts, 123/4 in. long by 4 in. diameter, made from Pontypool cold-blast pig iron. Those made from No. 1 pig iron--the most graphitic and costly--br
PREV.   NEXT  
|<   84   85   86   87   88   89   90   91   92   93   94   95   96   97   98   99   100   >>  



Top keywords:

chilled

 

article

 

account

 
castings
 
Bristol
 

Morgans

 
lining
 

wheels

 

alkaline

 

Pontypool


liquid
 

plowshares

 

serrated

 

brasses

 

bushes

 
crossings
 

artillery

 

tramway

 

railway

 
grinding

abstract

 
descriptions
 

graphitic

 

costly

 

common

 

milling

 

hammer

 
author
 

instanced

 

anvils


circular

 

exporting

 

numbers

 

presence

 

Captain

 

company

 

respect

 

impact

 

strength

 

fatigue


resistance

 

details

 

cutters

 

breaker

 

diameter

 

reputation

 
wrought
 

steeled

 

Palliser

 

combination