August 25, 1911] 



SCIENCE 



251 



Hop Standards: Considered from the Chemical 



Standpoint: H. V. Tartar. 

 Losses in the Storage of Coal: Horace C. Porter 



and r. K. Ovitz. 



The paper describes tests made by the U. S. 

 Bureau of Mines at various points during the 

 last three years to determine the loss in heating 

 value and the physical deterioration of several 

 kinds of coal while in storage. Tests at various 

 U. S. Navy Yards (Portsmouth, N. H., Norfolk, 

 Va., and Key West, Fla.) and at the Pittsburgh 

 station of the Bureau, on New Eiver (W. Va.) 

 coal, have been carried on for eighteen months 

 both in the open air and under water, so as to 

 show the amount of the saving accomplished by 

 the latter method. Pocahontas coal has been 

 stored in the open air on the Isthmus of Panama 

 for nine months, and is being tested to show the 

 deterioration of this grade in a hot climate. 

 Pittsburgh gas coal has been stored in open bins 

 exposed to the weather at Ann Arbor, Mich., and 

 also submerged under water, so as to determine 

 both the loss of heat value and the deterioration 

 in gas-making qualities (the latter phase of the 

 investigation being under the auspices of the Uni- 

 versity of Michigan and the Michigan Gas Asso- 

 ciation). Sheridan (Wyo.) sub-bituminous coal 

 (black lignite) was stored in outdoor bins at 

 Sheridan, Wyo., for nearly three years, and the 

 amount of deterioration and slacking under dif- 

 ferent conditions determined. 



The results show briefly that deterioration in 

 the open varies considerably with the kind of coal, 

 the Appalachian coals being only slightly affected 

 while the younger coals of the west, which differ 

 from the Appalachian in their chemical character, 

 are more easily oxidized and weathered. 



New Eiver coal loses less than 1 per cent, in 

 heating value during open-air exposure for one 

 year, and no loss at all occurs during storage 

 under water. The wetting of the coal by sub- 

 mergence reduces its evaporative power more than 

 enough to offset any saving accomplished through 

 the prevention of deterioration. The only ad- 

 vantage of submergence in case of this coal, there- 

 fore, is the avoidance of all risk of spontaneous 

 combustion. Pine coal deteriorates more in all 

 cases than run-of-mine. 



Pocahontas coal, during nine months' open-air 

 storage at Panama, lost only 0.3 per cent, in heat 

 value. Sheridan, Wyo., sub-bituminous lost 3-5 

 per cent, in heat value during three years ' storage 

 in outdoor bins and slacking penetrated only 

 about one foot from the surface. Pittsburgh gas 



coal stored in outdoor open bins lost nothing in 

 heat value during the first six months. 



Need of Professional Code of Ethics among Chem- 

 ists: Lucius P. Beown. 



Storage Battery Efficiency: J. S. Staudt. 



A New Modification of Gas Analysis Apparatus: 

 B. G. Klugh. 



Refractories and Laboratory Appliances made of 



Alundum: P. A. Boeck. 



The rapid advance in high temperature work 

 and furnace construction during the past few 

 years has necessitated the development of a high- 

 grade refractory material to withstand excessive 

 temperatures. Electrically fused alumina has long 

 been known to have exceptional refractory proper- 

 ties, but on account of the difficulties in the manu- 

 facture of articles of this material its use has been 

 limited. Fused alumina under the trade name of 

 ' ' alundum ' ' has been made for abrasive purposes 

 for the past ten years by the Norton Company, 

 Worcester, Mass., who have lately adapted this 

 material for refractory purposes. 



There are two varieties of fused alumina or 

 ' ' alundum ' ' made. 



One is a dark, brown, dense vitreous body having 

 a density of 3.9 and a hardness between corundum 

 and diamond. This is made by calcining bauxite 

 and fusing it in a water-cooled electric furnace, 

 where the impurities in the form of iron oxide, 

 silica and titanium oxide are reduced to a consid- 

 erable extent, leaving the material in the furnace 

 92 to 95 per cent, alumina. The other is a material 

 of higher purity, containing more than 99 per 

 cent, alumina, made by carrying the purification 

 process further. This is the material most gen- 

 erally used for refractory work. 



The alundum comes from the furnaces in pigs 

 weighing about five tons each, which are broken 

 up, crushed and graded to grain of a uniform 

 mesh. In making refractories of this material 

 grain of a suitable size or combination of sizes is 

 mixed with a refractory bond of a ceramic nature 

 and the pieces molded, pressed or cast into shape 

 and fired at high temperatures. The kind and 

 amount of bonding material, and the size or com- 

 bination of sizes of grain used, are varied to give 

 properties to suit the conditions under which the 

 articles are to be used. In this way their proper- 

 ties may be modified or controlled to adapt them 

 to any refractory use. Attempts have been made 

 to make articles of cast alundum, which have been 

 only partially successful. 



