REPORT OF DEPARTMENT OF METALLURGY. 269 



rence of this material that lias ever been exhibited. To this are added 

 illustrations of the api)li('ation of asbestos, inoludinj;' various kinds 

 of packings and covers for heated surfaces, threads of various sizes, 

 cloth used for various purposes, and in fact very fully illustrates the 

 application of the material. This collection is one of the fullest and 

 most complete that we have, and special thanks are due to the Johns 

 Company for their care and attention in its i)reparation, they having 

 gathered all the material and set it u]) in a very creditable manner. 



The materials used for various abrading and polishing purposes are 

 illustrated by a collection presented by R. J. Waddell & Co., New 

 York, and a collection of tripoli in its crude and prepared shape 

 by the Saint Louis Tripoli Company, Saint Louis, Mo. A large col- 

 lection of corundum, emery, and quartz in the lump and in various 

 sizes was presented by the Union Stone Companj-, Boston, Mass. 

 The preparation of barytes for various uses is rejireseuted by a collec- 

 tion presented by Messrs. Page and Krause, Saint Louis, Mo. 



Mucellaneous material. — The application of the regenerative system 

 of heating devised by Dr. Siemens is very fully illustrated by a large 

 series of drawings of furnaces for various uses presented by Messrs. 

 Richmond and Potts, Philadelphia. 



The use of the diamond drill in mining operations, esi)ecially for ex- 

 ploring purposes, is well illustrated by a collection presented by the 

 Pennsylvania Diamond Drill Company. This collection includes photo- 

 graphs of machines suited for various characters of work, illustrations 

 of the bit of the drill with a large number of cores taken out from dif- 

 ferent sections of the country, together with drawings showing the use 

 that has been made of the drill and some of the results obtained. 



Owing to the small space allowed the Museum for exhibition purposes 

 at New Orleans it was not possible for this department to show any- 

 where near all the material collected. At the same time, in order to 

 make the subjects as full as possible, selections were made from materials 

 already on hand, and the subjects of Economic Geology and Metallurgy 

 were represented at New Orleans by the following collections: 



In the first division of this collection — that of Economic Geology, or 

 the natural occurrence of materials of economic value — it is designed 

 to exhibit collections illustrating the difierent kinds and grades of the 

 ores of each metal, and also a few collections of non-metallic minerals 

 of economic importance. 



In the second division — that of Metallurgy — it is designed to exhibit 

 <-ollections representing the processes for the extraction of the metals 

 from their ores by specimens, where practicable, filling the gaps by 

 means of illustrations and descriptions and accompanying them by gen- 

 eral illustrations and descriptions so as to fully explain these processes. 



In making up the ore collection it has been designed to represent all 

 the different varieties of each ore and many of the most ])rominent min- 

 ing regions, so as to give a good gcnernl idea of the nature of the oc- 

 currences of the metals and also their distribution, but it has not been 



