GASKELL 



in the first gas attack at Ypres. 

 It consisted of a flannel bag pro- 

 vided with a mica window, and of 

 sufficient size completely to en- 

 velop the wearer's head and be 

 well tucked in round the neck 

 under the tunic. The flannel was 

 treated with a solution of sodium 

 carbonate, which combines with 

 free chlorine and thus purifies the 

 air that passes through. 



Subsequently, with the use of 

 phosgene gas by the Germans 

 helmets were impregnated with 

 sodium thiosulphate and sodium 

 phenate, and fitted with a valve 

 through which the exhaled air was 

 blown, making the helmet much 

 more comfortable to wear. The 

 advent of the use of gas shells made 

 it necessary to provide protection 

 against higher concentrations of a 

 much wider range of chemicals, and 

 this could not adequately be done 

 with impregnated fabric, with the 

 result that the box respirator orgas- 

 mask was introduced, but the latest 

 type of gas helmet was retained as 

 the reserve equipment in the British 

 Army. 



In the box type respirators, a 

 close-fitting mask on the face is 

 connected by flexible tubing to a 

 box containing the chemicals, and 

 carried on the breast from a strap 

 round the neck. The chemicals are 

 usually consecutive layers of active 

 absorbent charcoal and pumice im- 

 pregnated with sodium carbon- 

 ate and hexamethylenetetramine. 

 These will absorb all the gases used 

 up to now. (See Gas.) 



Gas helmet is also the name 

 applied to the breathing apparatus 

 used by rescue parties when enter- 

 ing a coal-mine after an explosion. 

 This consists of a head-covering 

 which excludes air, fitted with 

 goggles and a valve through which 

 the exhaled air is blown, and is fed 

 with oxygen carried in the com- 

 pressed state in small cylinders 

 attached to the shoulders. The gas 

 passes through a reducing valve to 

 lower its pressure, and is mixed 

 with the exhaled air after the 

 latter has been freed from carbonic 

 acid gas by treatment with caustic 

 soda in a separate chamber. 



Gaskell, ELIZABETH CLEGHORN 

 (1810-65). British novelist. Born 

 at Chelsea, Sept. 29, 1810, daughter 

 of T. Steven- 

 son, Keeper 

 o f Treasury 

 Records, she 

 was brought 

 up at Knuts- 

 ford, Cheshire, 

 PXlfcfc. and Stratford- 

 I on-Avon. In 

 a 1832 she mar- 

 ried William 

 Gaskell, a 



344O 



Unitarian minister and professor of 

 English literature at Manchester. 

 Her first novel, Mary Barton, 1848, 

 met with wide success and high 

 praise, and was followed by Ruth, 

 1853, and by her best known work, 

 Cranford, 1853, a charming picture 

 of village life founded on her recol- 

 lections of Knutsford. Other works 

 were North and South, 1855, 

 Sylvia's Lovers, 1863, several vol- 

 umes of short stories, and the excel- 

 lent life of her friend, Charlotte 

 Bronte, 1857. Mrs. Gaskell died 

 near Alton, Hants, Nov. 12, 1865, 

 and was buried at Knutsford. See 

 Mrs. Gaskell, C. K. Shorter, 1908 ; 

 Mrs. Gaskell : Haunts, Homes, and 

 Stories, Mrs. Chadwick, 1910. 



Gasket. Rope yarn used for 

 making joints in spigot and faucet 

 pipes. The yarn is rammed well 

 into the joint, and melted lead is 

 then poured in and caulked to 

 complete the joint. It is also a 

 cord or rope, of which the ends 

 of the strands are plaited, secured 

 to a ship's yard, to which a sail is 

 fastened. A gasket and eye is 

 formed by looping the end of a rope 

 and plaiting the loose ends. 



Gas Lighting. The use of gas 

 for illuminating purposes was first 



E ractically demonstrated by Wil- 

 am Murdock in 1779. It was not 

 for some years, however, that coal 

 ga& began to be used to any extent. 

 In 1798 Murdock used gas as an 

 illuminant in a Soho factory, and a 

 few years later he applied it to 

 cotton mills in Manchester. In 

 1810 the Gas Light and Coke Com- 

 pany was formed ; three years later 

 Westminster Bridge was lighted 

 with gas; and its use gradually, 

 though slowly, extended to street 

 and other forms of lighting. The 

 invention of the gas mantle, and 

 the consequent greatly increased 

 light obtained, put gas lighting on 

 a better basis to compete with 

 electric lighting. See Lighting. 



Gaslight Paper. Paper, used 

 for printing photographs, of such 

 sensitiveness to light that the 

 exposure behind the negative and 

 the development of the invisible 

 image thus produced can both be 

 done by gaslight or equivalent illu- 

 mination. The exposure is made 

 a few inches from the light ; the 

 development some feet away, and, 

 as a measure of precaution, hi 

 shadow. Gaslight paper was in- 

 troduced in America about 1897. 

 See Photography. 



Gas Liquor. Ammoniacal li- 

 quor which separates from coal 

 gas in the hydraulic main. The 

 liquid is collected in a well, and 

 contains practically the whole of 

 the ammonia yielded by the coal 

 in the process of distillation. The 

 ammonia is not present in the free 



GAS METER 



state, but is combined as sulphide, 

 carbonate, chloride, sulphate, 

 cyanide, ete. Sulphuretted hydro- 

 gen, phenols, and pyridine are also 

 present in the gas liquor. The 

 liquor is distilled to obtain the 

 ammonia, which is combined with 

 sulphuric acid to form sulphate of 

 ammonia, employed extensively as 

 a fertiliser. See Coal Gas. 



Gas Mantle. Device for in- 

 creasing the illuminating power of 

 coal gas. In 1885 Karl Auer, Baron 

 von Welsbach, an 

 Austrian scientist 

 who had been 

 studying the rare 

 earths, introduced 

 in Vienna the now 

 well - known gas 

 mantle, which 

 yields from four 

 to five times the 

 amount of light 

 given by the best 

 previous burners 

 for the same con- 

 sumption of gas. 

 Previous to the in- 

 vention of the 

 Welsbach burner 

 an attempt had 

 been made to em- 

 body something of' 

 the same idea in 

 fine platinum wire, 

 but not with any 

 particular success. 

 While various rare 

 earths have been 



' m *"% pro - 



Welsbach - Kern duction of gas 

 high-p ressure mantles, the 



b, b', air inlets ; used to-day is 



c, gas and air oxide of thoria, 

 mixer; d, burner containing about 

 1 per cent, of the oxide of ceria. 



Gas Manufacture. Gases have 

 become of rapidly increasing im- 

 portance in modern commerce, and 

 their manufacture on an extensive 

 scale forms a widespread industry. 

 The actual processes of manu- 

 facture are dealt with under the 

 respective headings of the gases 

 concerned, e.g. acetylene, carbon 

 dioxide, coal gas, helium, hydrogen, 

 water gas, etc. The manufacture 

 of hydrogen and helium has been 

 given a great impetus during the 

 Great War for filling balloons and 

 airships, and undoubtedly the 

 extended use of giant airships for 

 international and inter- oceanic 

 traffic will result in new methods 

 of production. 



Gas Meter. Instrument for 

 measuring gas. Gas meters are of 

 two kinds, the wet and the dry. 

 The former consists of two cylin- 

 ders with their axes horizontal and 

 concentric, one arranged to revolve 

 inside the other. The revolving 



