146 



SCIENCE 



[N. S. Vol. XXVII. No. 682 



to express the dynamical relations existing be- 

 tween the separate atoms of a molecule, and 

 thus the present conception of chemical bonds 

 and linkages be given a broader significance. 



The paper appears in full in the Astro- 

 physical Journal for November, 1907. Ad- 

 dendum, October 30, 1907. 



By reducing the results to zero weight of 

 the base and extending the curve h to zero 

 weight of the acid- forming element, the weight 

 with O3 both in base and as acid-forming ele- 

 ment is zero. Thus a wave-length is found 

 which is approximately that found by Angs- 

 trom for the absorption of ozone. 



Also a second absorption band in ozone cor- 

 responds to the second carbonate bands, found 

 at a longer wave-length. 



This is a very important confirmation of 

 the assumption made viz., that, " the oxygen 

 atom is the one chiefly responsible for the 

 selective reflection observed." 



The Decay of Phosphorescence of Oases: C. C. 



Trowbridge. 



The author described a new form of photom- 

 eter designed for the purpose of measuring 

 the rate of decay of luminosity of a phos- 

 phorescent gas. The photometer consists of a 

 track 3.5 meters long, made of two brass rods 

 under tension. On the track an electrically 

 controlled carriage runs which carries the 

 standard light. The standard light can be 

 moved away from a screen placed close to a 

 tube containing the phosphorescent gas to 

 points A, B, C , etc. The illumination on the 

 screen from the standard light is thus directly 

 compared with the luminosity of the gas, and 

 comparisons are made at A, B, G, etc., as the 

 gas fades. Seven readings can be made with- 

 in ten secorids, giving a variation of from 1/2 

 to 1/25 the original intensity of the phos- 

 phorescent gas. The entire apparatus is oper- 

 ated electrically, time being registered on a 

 chromograph. 



By means of this photometer the law of the 

 rate of decay of phosphorescence for gases has 

 been found. In this case, for air at about 0.1 

 millimeter gas pressure, the expression is the 

 same as that for the decay of phosphorescent 

 solids, or 



[a + uy 



Plotting the reciprocal of the square roots of 

 the intensities, in the case of one decay of 

 luminous gas, with the corresponding times 

 gives a perfectly straight line. An applica- 

 tion of the law to the grading of the light of a 

 body of phosphorescent gas as great in size as 

 a meteor train shows that the light of the 

 self-luminous meteor train can be explained 

 on the assumption that it is a gas phosphores- 

 cence, although the train may be visible for 

 thirty minutes. A certain brightening of the 

 sky around the radiant point at the time of 

 meteor showers which has been called the 

 " auroral light " is also explained by the ap- 

 plication of the same law. In the latter case 

 it is evident that the feeble phosphorescing of 

 many trains has combined to give a pale glow 

 in the regions of the heavens through which 

 the shower was taking place. 



Some Temperature Measurements tahen in the 

 Steel Worhs with the Wanner, Fery and Le 

 Chatelier Pyrometers: W. Campbell. 

 The author briefly described the instruments 

 used, methods of standardization and applica- 

 tion. The temperature readings obtained at 

 the blast furnace were: Metal, 1375° to 1250° 

 C. ; slag, 1425° to 1375°. At the Bessemer con- 

 verter, 1600° C, very hot blow; 1500° C. cool. 

 Average blows 1550° C. The steel was cast 

 at 1500° to 1460° 0. At the Open Hearth the 

 furnace temperatures varied from 1550° to 

 1705° C, the surface of the bath being 1705°. 

 The steel was cast at 1540° to 1460° C. The 

 temperatures of the gas producers varied 

 greatly, one set averaging 650° C, another over 

 850° 0. The most important readings were 

 taken at the Rail Mill, on the finishing tem- 

 peratures of steel rails. The readings with 

 the Fery pyrometer varied from 1000° to 1070° 

 C, whilst the Wanner averaged 1100° C. 



At this meeting Professor D. W. Hering 

 was nominated for vice-president and chair- 

 man of the section for 1908, and Professor 

 W. Campbell for secretary. 



At a meeting of the section held on Mon- 

 day, November 18, three papers were pre- 

 sented. 



