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Reduction of Error by Linear Compounding. By W. F. Sheppard, Sc.D., LL.M. Pp. 39. 
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Tidal Friction in Shallow Seas. By Harold Jeffreys, M.A., D.Sc., Fellow of St. John's 
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Plane Stress and Plane Strain in Bipolar Co-ordinates. By G. B. Jeffery, M.A., D.Sc., Fellow 
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The Aerodynamics of a Spinning Shell. By R. H. Fowler, E. G. Gallop, C. N. H. Lock and 
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A Selective Hot-Wire Microphone. By W. S. Tucker, D.Sc., A.R.C.Sc., and E. T. Paris, 
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Title, Contents, Index, &c., Vol. 221. Pp. 10. Price Is. 
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The Emission of Electrons under the Influence of Chemical Action. By O. W. Richardson, 
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The Problem of Finite Focal Depth revealed by Seismometers. By George W. Walker, 
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Eddy-Current Losses in Cylindrical Conductors, with Special Applications to the Alternating 
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The Blood Vascular System of the Tuatara, Sphenodon Pundatus. By Chas. H. O’Donoghue, 
D.Sc., Professor of Zoology in the University of Manitoba, Winnipeg. Pp. 78; 3 Plates. 
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On the Structure and Affinities of Acmopyle Pancheri, Pilger. By Birbal Sahni, M.A., M.Sc., 
University Professor of Botany, Lahore (Punjab); late Professor of Botany at the Hindu 
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On the Calcification of the Vertebral Centra in Sharks and Rays. By W. G. Ridewood, D.Sc. 
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The Life-History and Cytology of Synchytrium Endobioticvm (Schilb.), Perc., The Cause of 
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On a Periodic Structure in many Insect Scales, and the Cause of their Iridescent Colours. By 
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The Asymmetry, Metamorphosis and Origin of Flat-Fishes. By H. M. Kyle. Pp. 55; 7 Plates. 
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