206 



NATURE 



! N< iVEMBER 14. 191 8 



A-, a resull of these and other experimental 

 tests, and of visits to various mine rescue stations 

 throughout the country, the Research Committee 

 is able to make a number of valuable suggestions 

 and recommendations in the first report, with the 

 objeel ol increasing tin- safetj and efficiency of 

 both apparatus and wearer. 



In the report attention is directed to the serious 

 defects in existing apparatus, and the lines along 

 which improvement is desired are indicated. 

 Tribute is paid to the pioneer work ol Mr. II. A. 

 Fleuss, the designer oi the first oxygen mine 

 rescue apparatus. The photo of which Fig. 1 

 is a "reproduction shows Mr. Fleuss and a group 

 of miners equipped with this apparatus, and it is 

 of especial interesl in thai it records the first 

 application of such apparatus in mining. The 

 photo was taken at the time of the underground 

 fire which followed the explosion at Seaham Col- 

 liery, 1SS0 Si. The excellent work of Sir W. E. 

 Garforth (designei oi the "Weg" apparatus), Sir 



Fir., i.— Henry A. Fie 



S equipped with earliest Fleus 

 abam Colliery. i : 8i. 



John Cadman, and others, in increasing the effi- 

 ■ v of oxygen apparatus, is referred to, and 

 also that of Col. Blackett and Mr. Mills, of New- 

 castle, in connection with liquid-air apparatus. 



Only the so-called two-hour types of apparatus 

 have been dealt with. These may be divided into 

 three clai ies : (1) Those in which the oxygen 

 supply is derived from a cylinder of the com- 

 pressed gas; (2) those in which the oxygen is 

 derived from the evaporation of liquid air; 

 (3) those in which the oxygen supply is produced 

 by the chemii al action of water vapour and carbon 

 dioxide on oxylith (KNaO 1. 



The repoi that the compressed oxygen 



type is mosl favoured in this country, there being 

 1720 apparatus of this type in use compared with 

 ninety-six ol the liquid-aii type, whilst class ;, 

 has hitherto not been em iloyed here. For those 

 who are not acquainted with mine res< ue 

 apparatus a description <<\ a compressed oxygen 

 NO. 2559, VOL. I02] 



type ma) be of interest. The apparatus about 

 In lie described is the " I'roto " (which is the 

 development ol the original Fleuss apparatus). 

 The description is quoted from the report: — r 



The apparatus has the merit of simplicity. The 

 circulation is dependent on the lungs of tin- wearei 

 breathing being entirel) through the mouth. The 

 cylinders I', together hold 280 litres of oxygen 

 nuclei .1 pressure "I 120 atmospheres. Th< reducing 

 valve (' (Fig. 41, whin correctlj adjusted, allows 

 a constant How oi oxygen of 2 litres a minute to pass 

 into the breathing circuit. The makers also suppl) 

 reducing valves, which can I" set b) the wearer to 

 give discharges ranging from between o-6 and ; litres 

 per minute. The oxygen passes through a flexible 

 tube I'' tunning over the wearer's lefl shoulder, and 



enters the bag at X, where- it joins the air being 

 drawn into tin- lungs. Light mica valves are fitted 

 in the lubes at M and I. to control the direction oi 

 the Mow nl the air. The breathing-bag, which is ol 

 rubber, is divided into two compartments by a parti- 

 tion reaching nearly la the bottom, and in the bottom 

 of the bag is placed a charge of caustic soda weighing 

 3 to 5 lb. Either stick-soda is em- 

 ployed or coke nuts coated with 

 caustic. The air, in travelling from 

 one compartment of the bag to the 

 c ilber, has thus to find its way 

 through the soda, and in doing so 

 the carbon dioxide is absorbed. 

 I!v shaking the bag from to time, 

 new surfaces of the absorb* n 

 exposed to the aii . and the absorp- 

 tion of carbon die ixide is lac ilitated. 

 A saliva trap /. is fitted under lb' 

 exhaling lube. Tin- pressui 1 ■ ■■ 

 which is carried in a pocket in front 

 of the bag, is connected to the 

 oxygen supply by means of a highly 

 flexible metal lube \V. The wearer 

 can thus read his own gauge. A 



relief valve, opei ated l>\ the w earer, 



is placed in the bag at K. Fig. 4 

 shows bow, by means of a strong 

 steel neck-, ibe main valve wheel II 

 is brought to the front within reach 

 of the wearer. 



A by-pass short-circuits the 

 reducing valve C. Oxygen can 



be discharged through the by-pass 

 by opening the cock I. V is the pressure-gauge 

 valve. It is opened only when the gauge is to 

 be read. The weight of the apparatus is about 

 36 lb. Needless to say, the heavy oxygen 

 cylinders are responsible for the- greater propor- 

 tion of this. 



Other types of compressed-oxygen apparatus 

 diffei considerably in detail from the " Proto " 

 apparatus just described. For example, in the 

 Draeger (German) and Meco (English) an artificial 

 circulation of air through the apparatus is pro- 

 dueeil by admitting the oxygen through an in- 

 jector nozzle at a constant rate, an air circulation 

 of from 50 to ho litres a minute being thereby 

 indm ed, independent of the lungs. 



Face-masks, in place of the mouthpiece shown 



in the illustrations of tin- " Proto " apparatus, are 



sometimes supplied. Experimental tests on these 



have shown that they are a source of grave 



to the wearer, when in a poisonous atmo- 



