Ixxiv. 



the dates of MSS. In connection with colours it may be of 

 interest to mention that a coloured photograph of the moon 

 shews a general surface of olive green with spots which have 

 orange, purple, and blue tones. Attempts have been and 

 are being made to produce a light which shall exactly resemble 

 daylight, and enable certain trades which require daylight 

 to be carried on at other times ; but no perfect success has 

 yet been obtained, though much has been done. The pro- 

 duction of india rubber synthetically has been accomplished, 

 at a price to compete with natural rubber, to which it will be 

 a serious rival. Another valuable discovery is that of 

 " non-flaming " celluloid, which possesses all the other 

 properties of celluloid, but burns in a safe manner and is free 

 from the dangers hitherto associated with that substance. 



ENGINEERING. 



The Engineering subject which is still most occupying 

 public attention is probably aviation, both in regard to 

 aeroplanes and airships, though I do not think that any 

 really important improvements have taken place in either 

 during the past 12 months. , But the untried and possibly 

 very important effects which these may have in case of war 

 have given rise to a great deal of discussion and speculation. 

 In the wars that have taken place since their introduction, 

 the opposing forces have not been by any means in the front 

 rank in aviation, and this fact may account for the com- 

 paratively small part which it has played in the conflicts 

 still, aeroplanes have been used with sufficient effect to shew 

 that they are likely to be important munitions of war in the 

 future, both for prospecting and offensive purposes. At the 

 International Aero Exhibition early this year, many different 

 types were shewn. The lifting power of aeroplanes has 

 reached a high pitch, but the lateral stability leaves much 

 still to be desired, and is more or less dependent on the skill 

 of the pilot. Until this has been overcome, either by the 



