NOTES 47S 



(September 3, 1920) a summary of his most recent work on the structure oi 

 the metals. A narrow beam of monochromatic X-rays passed through the 

 powdered metal produces a pattern of fine lines on a photographic plate due 

 to the reflexion of the X-rays from the faces of the crystals — one line for 

 each kind of face. From the positions and intensities of these lines the posi- 

 tions of the atoms in the metallic crystals can be calculated. The results show 

 that the atoms of calcium, palladium, and iridium, like those of platinum, have 

 a face-centred cubic arrangement. Titanium has a centred cubic arrange- 

 ment like chromium and iron ; tantalum one like tungsten. The structures 

 of cadmium and zinc are hexagonal, close packed, and elongated in the direc- 

 tion of the hexagonal axis ; this corresponds to a close-packed arrangement of 

 prolate spheroids. The atoms of iridium are arranged in a face-centred tetra- 

 gonal lattice elongated 6 per cent, in the direction of one of the cubic axes, 

 so that it, also, is a close-packed arrangement of prolate spheroids. The 

 structure of ruthenium resembles that of cadmium and zinc, except that its 

 lattice is shortened where that of the others is elongated. It is thus a close- 

 packed arrangement of oblate spheroids. 



A second note in Science (September 24) by D. M. Dennison, writing from 

 the same laboratory, gives details of the structure of ice-crystals. No 

 details as to the experimental method are supplied, but it is stated that the 

 results indicate that the molecular formula for ice is H4O2 or 2(HoO). 



Col. W. B. Breeley, the new chief forester of the U.S.A., who has lately 

 completed an inspection of the natural resources of Alaska, is reported to have 

 said [Science, September 10, 1920) that that country could supply pulpwood 

 for the annual manufacture of 1,500,000 tons of paper in perpetuity. This 

 is about one third of the present consumption of paper in the States, and 

 approximately equal to its import from Canada. In view of the present 

 cost of paper, it is to be hoped that the Alaskan supply will be tapped forth- 

 with, and that some of the Canadian surplus will then reach this country at a 

 reasonable price. 



The Canadian Commission of Conservation has issued a long report on the 

 Water Power of British Columbia, from which it appears that the surveyed sites 

 in that Province would yield no less than 3,000,000 horse-power, while there 

 are, in addition, large areas virtually unknown and considerable possibilities 

 of water storage. 



Another report on Power in Alberta contains an account of the enormous 

 coal deposits in that district. It contains about 87 per cent, of all the coal 

 in the Dominion (estimated at over a million million tons— Great Britain 

 about 200,000 million tons). Unfortunately, three-fifths of the Alberta 

 deposits are of the lignite type ; but, even so, the supply of good coal in Alberta 

 exceeds that in this country. Incidentally it may be noted that the U.S. 

 Bureau of Mines has completed plans for co-operative research on the car- 

 bonisation of lignite, a fund of $200,000 having been provided for the erection 

 of the necessary plant in N. Dakota. 



Special Report No. 3 from the Fuel Research Board entitled The Coal 

 Fire (H.M. Stationery Office, price 4s. net.) contains an account of the very 

 interesting results obtained by Dr. Margaret Fishenden from her experiments 

 with ordinary domestic grates, performed at the instance of the Air Pollution 

 Advisory Board to the Manchester Corporation, 



The main work was directed towards the measurement of the heat radiated 

 by a fire into the room. This heat was estimated by suitably integrating 

 thermopile measurements taken at different points on the surface of an 

 imaginary hemisphere with its centre at the centre of the fire. The radiant 

 efiiciency of the fire was defined as the ratio of the total radiation so estimated 

 to the calorific value of the coal burnt. The results showed that, while the 

 type of grate used is relatively unimportant, yet the old-fashioned grate is 

 definitely more efficient than the modern barless grate, the actual figures 



