Febeuakt 5, 1915] 



SCIENCE 



201 



Castle, Colo., December 16, 1913, in which 3Y 

 men were killed; and one at Eccles, W. Va., 

 April 28, 1914, in which 181 lives were lost. 

 The general ventilation in most of the mines 

 involved in explosions was good, but the defect 

 in certain mines was in permitting the local 

 accumulation of gas through not bratticing up 

 to the face of gaseous entries or working places. 

 One of the great disasters was probably caused 

 by the use of dynamite for blasting, and by 

 disobedience in firing a shot or shots when 

 miners were in the mine, in spite of the fact 

 that an outside shot-firing system had been 

 installed. 



Other lesser disasters occurred during the 

 year. Many shot firers lost their lives in the 

 Pittsburg, Kans., district, and in Oklahoma, 

 Indiana and Iowa. Although the system of 

 employing shot firers to fire the shots when- 

 all others are out of the mine lessens the num- 

 ber of deaths, yet in many districts the meth- 

 ods of shot firing employed are still so ex- 

 tremely hazardous that only the most reckless 

 men are willing to act as shot firers. In any 

 mine in which this system is used there seems 

 to be no good reason why shot firing from 

 vwthout the mine by electrical means should 

 not be employed, at least if permissible explo- 

 sives are not used. 



Director Holmes strongly urges the pur- 

 chase by the government of the grounds on 

 which the experimental mine is situated. He 

 declares that the Bureau of Mines should own 

 these grounds, now merely leased, in order to 

 safeguard the large expenditure already made 

 in developing the mine thereon and equipping 

 it with expensive appliances. 



Looking to the future, the director observes 

 that, despite the progress made in ascertain- 

 ing the nature of mine explosions and in de- 

 vising methods of prevention, they still con- 

 tinue to occur, and it is to be feared that com- 

 plete prevention will be difficult, owing to the 

 inherent difficulty of eliminating errors of ob- 

 servation, judgment, or understanding from 

 among miners or mine officials. Thus, one of 

 the shocking disasters of the past year was 

 brought about because of one man's willing- 



ness to risk the sacrifice of not only his ovra. 

 life, but the lives of many others in order to 

 gain a few tons of coal. It is difficult to meet 

 such a case, and yet with the progress that is 

 being made in the methods of preventing or 

 limiting explosions, it is certain that hereafter 

 in a well-protected mine properly cared for 

 there will be much less danger of a widespread 

 explosion. 



THE UNIVEESITT OF CINCINNATI BUREAU 

 OF CITY TESTS 



The Bureau of City Tests aids the city in 

 two ways. It helps the government to pur- 

 chase the best materials, by examining the 

 dealers' samples, and, by making further tests 

 from time to time, enables it to receive sup- 

 plies of good quality throughout the year. 



Cincinnati is one of the first large cities to 

 purchase coal under competitive bidding in 

 accordance with well-drawn specifications. 

 AU its purchases are made on the British 

 thermal unit basis. In submitting bids, deal- 

 ers guarantee a certain number of heat units 

 per pound, and a certain percentage of ash. 

 The cost per heat unit in the various bids is 

 then calculated and the contracts awarded. 

 All moisture in excess of the amount normally 

 present is deducted from the tonnage delivered. 

 The result of this new system has been the re- 

 ceiving of a good uniform grade of coal. 



The bureau tested the 450 or more carloads 

 of cement used, during the year, for various 

 city improvements. In spite of the fact that 

 only standard brands which have proved de- 

 pendable are used, 11 carloads of cement of 

 poor quality were rejected. The steel em- 

 ployed to reinforce concrete work is tested 

 physically, and of this but one questionable 

 sample was received. 



By testing fire hose, the city saved $11,000 

 on the contract of 1912, and about the same 

 amount on that of 1914. The bureau anal- 

 yzes samples without any knowledge of the 

 bidders' prices, and contracts are let on a 

 quality basis to the lowest bidder whose prod- 

 uct conforms to the standard undervsrriters' 

 specifications. The satisfactory performance 



