ASTRONOMICAL AND METKOllOLOOICAL WORKERS. 45 



both b and c would, from the argumont by which they were 

 introduced, be expected to be small compared to la (N - l)/m. 



To test this last formula the results of Lorenz's very delicate 

 experiments are available, as he has determined n and d for a 

 number of liquids at 10°, 20\ and for their vapours at 100^; from 

 the results for 10° and 20°, we can tind the constant and c, tlie 

 constant ought to be the same as the value of (n— D/d for the 

 vapour, and this is found to be accurately the case in 4 out of 

 the 5 liquids available for the comparison. 



In this manner, Gladstone's formula is established and extended 

 to meet the difficulty of its incomplete bridging of the change of 

 state from liquid to vapour. 



Thursday, August 30. 



This Paper has not received the final corrections of 

 the Author, owing to a mistake for wJiicJi he is not 

 responsible. 



The following pages contain the result of an attempt, made in 

 the midst of other pressing duties, to collect into a concise form 

 the history of what has been done in New South Wales for 

 Astronomy and Meteorology. As it is the first attempt to do so, 

 it is hardly necessary to say that it has involved a considerable 

 amount of trouble, and that many points are not yet fully made 

 out, but a search, specially amongst astronomical publications, 

 has cleared up many points of interest which at one time seemed 

 buried in oblivion. I have also had, through the courtesy of the 

 Principal Under-Secretary and others, access to official records 

 which otherwise would not have been available. 



Lieutenant Dawes. 



In 1786, Nevil Maskelyne, Astronomer Royal, in a paper, read 

 before the Royal Society, points out that Halley's celebi^ated 

 comet of 1682 would re-appear in 1788, and be first visible in tlie 

 southei'n skies, and hence it was that a young and energetic 

 Astronomer found himself with all the incongruous surroundings 

 in the first fleet of ships bound to Australia. No time was to be 

 lost in setting up the Observatory, for although the comet was 

 not expected until September, 1788, it might be before its pre- 



