Geology and Mineralogy. 495 



of the metals experimented upon being determined by the limit 

 of this rise. These thermometers were graduated by the tem- 

 perature of the boiling points of water, naphthalene, benzophe- 

 none, and sulphur, and the freezing point of water. The chief 

 difficulties which presented themselves were : Variations in the 

 resistance of the connections between the thermometer coil and 

 the resistance coils ; variations in the temperature of the resist- 

 ance coils themselves ; the rise in temperature of the thermometer 

 coil due to the current used when measuring its resistance ; the 

 presence of currents due to thermal effects ; superheating during 

 distillation, and radiation from the source of heat to the ther- 

 mometer ; the changes in boiling points due to changes in the 

 barometer; oxidation of the metals when fluid. 



The mean values obtained are as follows : boiling point of 

 aniline 184°-27, of methyl salicylate 223°"12, of mercury 357°-60. 



The results given bear out the following conclusions : I. That 

 although the curves of platinum temperature obtained from 

 different thermometers vary considerably, intermediate tempera- 

 tures deduced from these curves are in practical agreement. II. 

 That thermometers made and graduated as described may be 

 used for the accurate determination of temperatures up to about 

 500° C— Proc. Roy. Hoc, No. 294, p. 220. 



6. True weight of a cubic inch of distilled water. H. J. 

 Chaney has obtained the following value for the weight of a 

 cubic inch of water, 252*286 ± - 002 grains, of which grains the 

 imperial pound contains 7000 grains, with £=62°, and the barom- 

 eter at 30 inches. — Proc. Boy. Soc, No. 294, p. 230. 



7. Heat as a Form, of Energy, by R. H. Thurston. 261 pp. 

 12mo. Boston and New York, 1890 (Houghton, Mifflin & Co. 

 The Riverside Science Series, vol. iii).— This is a very readable 

 presentation of the subject of Heat, particularly in its application 

 as a motor. It opens by developing the growth of the modern 

 idea of heat as a kind of energy, and goes on to explain the 

 science of thermo-dynamics. After this comes the subject of the 

 transformation of heat into mechanical work with an account of 

 gas and coal engines, their growth and present limitations, and 

 the possible directions of progress in the future. 



8. Hound, Light and. Meat. A class book for the elementary 

 stage of the Science and Art Department, 223 pp. ; by J. 

 Spencer. Magnetism and Electricity. 163 pp. By J. Spencer. 

 London, 1890. (Percival & Co.) — These little volumes are exam- 

 ples of the many elementary science text-books called out by the 

 English system of examinations, but which are fitted to be useful 

 in a larger field. They include the fundamental principles in the 

 several branches of physics named, with numerous simple diagrams 

 and an abundance of exercises, for calculation and experiment. 



II. Geology and Mineralogy. 



1. Geological and Palceontological relations of the Goal and 

 Plant-bearing beds of Pakeozoic and Mesozoic age in Eastern 

 Australia and Tasmania; with special reference to the Fossil 



