VII. METALLURGY. 66? 



241 5e. Appliances for testing Gold and Silver. 



All these objects date from the time of the first quarter of the 

 18th century, and are the property of His Highness Prince Pless, 

 of Fiirstenstein Castle. The Breslau Committee. 



2458. Gay Lus sac's Apparatus for assaying Silver by 

 the Wet Way. Aug. Bel and Co. 



Copper cistern lined with resinous cement to contain the normal solution of 

 salt, TOO standard measures of which correspond with 896-thousandth of fine 

 silver in the assay. Funnel for use in filling the cistern. Pipette of 100 ec, 

 for use with normal solution. Pipette for use with decimal salt solution. 

 Pipette for use with the decimal silver solution. Cage for conveying the bottles 

 to the shaking apparatus. Shaking apparatus, filled with 10 assay bottles in 

 position for use. Dark case for bottle, containing the decimal silver solution. 

 Case in which the assay bottle is placed during the addition of the normal 

 solution to the assay. Hollow pillar, with sponge for absorbing the excess 

 of liquid from the front pipette during the adjustment of the level to gauge 

 mark. Water bath used for heating assay bottles during the solution of 

 assay pieces. Bellows used for removing the nitrous fumes from the assay 

 bottles. Whisk used for stirring the salt solution in the cistern. 



2761. Chart with Photographs of an Assay-Balance for 

 Buttons of a Weighing-out Assay-Balance and of a Blow- 

 ing Apparatus. C. Osterland, Freiberg, Saxony. 



The balances represented by the photographs have the columnar lifting 

 apparatus constructed by the exhibitor, which not only allows of the beam 

 being raised from the outside, but which renders the displacement of so light 

 a beam impossible. Assay balances of this kind have been made by the 

 exhibitor, which weigh to the 20th or 40th of a milligramme. 



2762. Improved Furnace for Fuddling Iron. 



Jeremiah Head, M.Inst.C.E* 



The object is to utilize a portion of the waste heat which ordinarily is 

 discharged from the chimney, by causing it to heat air to be afterwards s"up- 

 plied for the combustion of the fuel. Part of the chimney is enlarged into a 

 chamber, having a vertical partition extending nearly to the top. One half of 

 the chamber thus divided contains a cast-iron stove pipe, and the other half is 

 provided with a damper. 



When the damper is withdrawn the heated products of combustion take 

 the nearest route to the chimney, but when it is closed they are obliged to 

 pass by the more circuitous route, heating the stove pipe on the way. 



The air for combustion is injected, by means of a steam jet, into a funnel 

 connected with one side of a divided box, upon Avhich the stove pipe stands. 

 Moistened with the steam it becomes a powerful absorber and radiator of 

 heat. It passes through the heated stove pipe, and afterwards through the 

 back of the furnace into a closed ash-pit, and a portion through tuyeres into 

 the space above the fuel. 



It has then attained a temperature of about 650 deg. Eahr. The con* 

 sumption of coal of this furnace has averaged 12 cwt. 2 qrs. 11 Ibs. per ton of 

 puddled bar over two months of ordinary work, including lighting up and lost 

 heats. This is about one half of the usual consumption of fuel. The iron 

 (refined) used per ton of puddled bar in the same time averaged 20 cwt. 

 2 qrs. 26 Ibs. The heating chamber is surmounted by a boiler, intended still 

 further to utilize the waste heat. This, however, is not essential, and is hardly 

 worth the extra expense. An ordinary iron-cased chimney is preferable. 



