Chapman. — On Temporary Stars. 139 



List of Calls suited to the Maori Trumpet. 

 Officers. Sick call. 



Sergeants. Salute for guard. 



Fall in. Alarm. 



Men's dinner call. Charge. 



Sergeants' dinner call. Fire, and Cease fire. 



Fatigue. Extend, and Close. 



Picquet. General salute. 



Orders. 



Art. XXIII. — On Temporary Stars. 



By Martin Chapman. 



[Read before the Wellington Philosophical Society, 6th September, 1905.] 



The appearance of a so-called temporary star is always an event 

 of great importance to all interested in astronomy and its kindred 

 sciences. The event apparently involves a catastrophe of such 

 colossal magnitude that it almost transcends our powers of 

 imagination fully to realise it. A star which perhaps to our 

 view is so insignificant as to be visible only in a powerful tele- 

 scope — say, of the tenth or twelfth magnitude, or perhaps not 

 visible at all — suddenly increases in splendour until it shines as 

 a third- or second- or indeed even first -magnitude star. If our 

 sun were to increase in heat- and light-giving activity in a 

 similar proportion there can be no doubt that all planets would 

 be rendered red- or white-hot. if they were not dissipated into 

 vapour. 



After this enormous development of light and heat the new 

 star in a few days or weeks shows manifest signs of waning. 

 This waning proceeds so rapidly that at the end of a few months 

 the star is no longer visible to the naked eye, and can only be 

 perceived through powerful telescopes. Its final appearance is 

 also remarkable : it presents the appearance of a planetary 

 nebula — that is, it appears to be a nebula of no great intensity 

 of light, having a minute disc like a planet ; but the fact that 

 it has any visible disc is a proof of its colossal dimensions. No 

 " Nova " has. so far as I am aware, yet. shown an appreciable 

 parallax : it follows that to have any disc visible to us its dia- 

 meter must exceed that of the earth's orbit- 

 That such a vastly colossal globe of glowing matter should 

 p it with its heat in a few months is at first sight exceedingly 

 surprising, and has led to the suggestion being made that the 

 actual quantity of matter heated must be very small. How 

 otherwise, it may be asked, can it be ? A body like the sun is 



