IOO REPORTS ON INVESTIGATIONS AND PROJECTS. 



and that the changes appear to be governed entirely by the quantity of gas 

 which is set free. In other words, when the quantity of lava within the basin 

 remains practically constant, but the quantity of gas given off increases con- 

 siderably, there is a considerable rise in the temperature corresponding to it ; 

 and similarly, when the quantity of gas again diminishes, the temperature 

 falls appropriately. Inasmuch as these observations at the crater are still 

 going on, exact figures are not yet available. It proved practicable to de- 

 scend into the crater, to collect a considerable quantity of the gas as it 

 emerged from a fountain of liquid lava, to seal it away in glass tubes with- 

 out its having come in contact with the air at all, and to transport this gas. 

 to Washington safely, for detailed study. It is also practicable to ascertain 

 the composition of the smoke cloud, which contains considerable matter 

 which is not gaseous. Samples of the liquid lava taken directly from the lava 

 lake were obtained last year. With this material we entertain the hope that it 

 Avill prove practicable to determine the character of the chemical reactions 

 within the gases, between the gases and the liquid lava, and between the 

 gases and the air. If this can be done, considerable light will be thrown 

 upon the character of the chemical reactions which participate in the activity 

 of this particular volcano. In view of the fact that several recent writers 

 have sought to prove that water has no part in volcanic activity, it may be 

 mentioned that out of the gases which we collected directly from the boiling 

 lava something like a half pint of water condensed in the tubes on cooling. 



Brief reviews of the papers published by members of the laboratory staff 

 during the current year follow : 



(i) Ueber den Durchgang des Lichtes durch inaktive durchsichtige Krystallplatten 

 mit besonderer Berucksichtigung der Erscheinungen im konvergent polar- 

 isierten Lichte. Fred. Eugene Wright. Tschermak's Min. Petrogr. Mitt., 

 30, 171-232. 191 1. 



A German translation of "The transmission of light through transparent 

 inactive crystal plates, with special reference to observations in convergent 

 polarized light" (Am. Jour. Sci. (4), 31, 157-21 1, 1911). Reviewed in Year 

 Book No. 9 (1910), p. 100. 



(2) On powers of ten. Walter P. White. Science, 35, 38-40. 1912. 



Physical magnitudes, as written, usually consist of two parts, the signifi- 

 cant figures and a power of 10. Ordinarily, all powers of 10 are liable to be 

 used. If restriction is made to those powers which are also powers of 1,000, 

 as is now done by many writers, greater uniformity is secured among dif- 

 ferent writers, confusion is less likely, and the memory is aided, since in 

 most cases there is no doubt which power of 1,000 is the right one. Num- 

 bers are still more readily comprehended and remembered if the power of 

 1,000 is indicated by a word, such as one of the prefixes milli, mikro, kilo, 

 mega. These prefixes, however, can only be used in connection with units 

 having names (e. g., megadyne, mikrovolt, millimeter) ; it is greatly to be 

 desired that some convention should be established by which they could also 

 be used for such quantities as expansion coefficients, degrees of precision, etc. 



