322 PROCEEDINGS OF SECTION A. 



eye-piece which is suggested should prove satisfactory. Nearly all 

 astronomical research is based on observations taken with a transit 

 circle. The observatories of Sydney, Melbourne, Adelaide, and Perth 

 are equipped with good transit telescopes, and it is proposed that 

 Australia should " take permanent charge of that portion of the 

 southern sky situated between 20° and 60° declination. Perth has 

 already committed itself to the unit 31°-41° ; Melbourne might be 

 asked to take the most southerly zone, 51°-61° ; Svdnev, 41°-51°; and 

 Adelaide, 21°-31°." 



If transit observations hitherto made had been properly co- 

 ordinated, it would not be possible, as it now, unfortunately, is, for 

 an astronomer to be unable to find in existing catalogues a number of 

 well- determined reference points in the particular field he is investigating 



This standard work is to be based on two main principles— (a) A 

 list of stars to be prepared siich that where possible three stars are in- 

 cluded in each square degree ; (6) each observatory to take a definite 

 zone, either 10° or 20° of declination (one or two units), and constantly 

 observe the same stars, taking at least three first-class observations of 

 each star every 10 or 12 years. 



There should be a list of fundamental stars. The Royal Observa- 

 tory at the Cape and the Argentine National Observatory might keep 

 up the positions of these. The secondary standards should contain 

 three or four stars per hour of right ascension for every 2° of declina- 

 tion, and include all the fundamentals. At the commencement of the 

 work one year is to be given to observing the secondary standards ; 

 and as soon as the list has been completely observed the work is to 

 begin again in the same way. By such co-operation over-lapping of 

 work, as well as important omissions, will be made impossible ; also 

 all transit observers engaged in it will feel that the whole of their work 

 is important and will certainly be used, and therefore will themselves 

 become more interested and accurate, and a large section of the sky 

 will have been carefully explored, so that workers will find in it well- 

 determined star-positions. 



11.— ON THE PHOSPHORESCENCE OF GLASS EXPOSED TO 



SUNLIGHT. 

 By R. C. YATES. 



[CoMMtTNICATED BY PROFESSOR BrAGG, M.A.] 



[Abstract.] 



Certain kinds of glass, on being exposed to strong sunlight, acquire 

 a violet tint. This fact has already been observed. The author now 

 showed that glass tinted in this way phosphoresced on being heated, 

 and the light was easily visible in a dark room. There was an obvious 

 parallelism between this effect and the thermoluminescence which could 

 be induced in certain substances, particularly by cathode rays. 



