296 SCIENCE PROGRESS 



will be lost, and only an inferior type of man will be attracted to industrial 

 work. 



Bulletin No. 4 of the Department of Scientific Industrial Research deals 

 with Solid Lubricants. Of these graphite is by far the most important, used 

 either dry or in colloidal solution with water or a neutral oil. It possesses 

 in a marked degree ability to adhere to metallic surfaces, and there to produce 

 a smooth unctuous surface. The other solid lubricants — talc and mica — 

 are not so good in either of these respects, and are, moreover, not nearly as soft, 

 the best quality talc excepted. The most important artificial graphites are 

 those produced by Dr. Acheson in the U.S.A., and by the Graphite Products 

 Ltd., of Battersea. Acheson No. 1,340 contains over 99 per cent, pure carbon, 

 98 per cent, of which is in the form of particles less than ^Is inch in diameter. 

 When converted into colloidal form by suitable means, it is sold as Aquadag 

 (with water, containing 98-7 per cent, graphite) and Oildag (with oil, containing 

 97-6 per cent, graphite). Foliac Flake Graphite No. loi (Graphite Products 

 Ltd.) contains 9995 per cent, graphite, but is comparatively coarse. When 

 ground finer, it is known as Foliac No. 100 and contains 99*6 per cent, graphite, 

 the chief impurity being silica. 



The great advantage of graphite as a lubricant arises from the fact that 

 it fills up pits, etc., in the metal surfaces, and by coating and impregnating 

 them makes it diflScult for them to seize. Dry it is used, for example, in 

 lace-making machines and chocolate machinery, to avoid the spoiling of the 

 material by ordinary oil, and in bottle-making machines, where the temperature 

 is so high that the oil would burn away. Colloidal graphite mixed with neutral 

 oil finds wide uses, especially with heavy bearings, worm gear, chain drives, 

 and under suitable conditions with steam-engines. The chief disadvantage 

 is the tendency of the graphite to flocculate in the presence of electrolytes ; 

 this makes it undesirable for use with internal combustion engines having an 

 oil-circulation system, unless, indeed, it is mixed with highly purified neutral 

 oils, on account of the danger of the choking up of oil- pipes, oil-grooves, etc., 

 with the precipitated graphite. With splash-oiling systems this danger does 

 not arise, the precipitated graphite merely accumulating in the bottom of the 

 engine. Aquadag is used in wire-drawing metal filaments for electric lamps, 

 and is apparently the only non-oily lubricant which has given satisfaction 

 for the purpose. The whole of this Bulletin (which can be obtained through 

 any bookseller, price 6^^.) is most interesting, and it is recommended to the 

 notice of all who have occasion to use lubricating materials. 



The world-wide scarcity of fuel and the great and apparently permanent 

 increase in the cost of coal have once more revived interest in the possibilities 

 of peat as a fuel. In order that some of the fundamental facts concerning 

 this matter might be brought before the public, the Fuel Research Board 

 has issued, as a separate report, a lecture on " The Peat Resources of Ireland," 

 delivered to the Royal Dublin Society by Prof. Pierce F. Purcell, Assoc. 

 M.Inst.C.E., on March 5 . It appears that the chief obstacle preventing the use 

 of peat on a large scale is its watery character in the natural state. To drain 

 a bog properly requires from three to five years, and even then it contains 

 less solid matter than cow's milk 1 The figures are : — undrained down to 

 5 per cent, solid, drained 9-12 per cent., cow's milk 12-15 per cent. To obtain 

 one ton of normal air-dried peat (which contains 25 per cent, of water), 

 it is thus necessary to remove and dry from 6 J to 15 tons of the raw material, 

 the exact weight depending on the thoroughness with which the bog has been 

 drained. The drying problem is a very serious one. To use heat is most 

 uneconomical, because so large a proportion of the final product is required 

 to evaporate the water. Thus to obtain 100 lb. of 33J per cent, wet peat 

 from 70 per cent, wet peat requires no less than 41 lb. of the final product — 

 even supposing the drying apparatus to have an efi&ciency as great as 60 

 per cent. Pressure alone, in the absence of heat, will only reduce the moisture 



