xxxii. New Zealand Institute. 



a poisonous compound which when in large quantities causes sickness 

 and death, we can realize how vastly important the absence of smoke 

 may be to the health of future generations. 



At the same time it must be admitted that gas has as yet not been 

 fairly treated j it has been regarded almost entirely as a means of 

 lighting, not sufficiently as a means of heating, and hardly at all as a 

 motive-power. Dr. Siemens (who has protested strongly against this 

 mistake) confidently predicts that, before many years have elapsed, we 

 shall find in our factories and on board our ships, engines, with a fuel 

 consumption not exceeding 1 lb. of coal per effective horse-power per 

 hour, in which the gas-producer takes the place of the present steam- 

 boiler. 



With regard to electricity as a motive-power, electric railways are 

 already in existence in Ireland and in Germany ; but scientific men 

 seem of opinion that, except in cases in which natural sources of 

 energy, such as bills and waterfalls, are found, it will be long before 

 electric power can take the place of steam on ordinary railways. I 

 need not point out, however, that this is a country in which such 

 sources of energy abound everywhere. I trust that at no distant 

 day the force which is now applied in the form of friction necessary 

 to hold back the trains in their descent of the Rimutaka Hill, 

 and which is now dissipated and lost in wear and tear, may be utilized 

 for propelling the engines for miles of their journey along the level 

 country. 



Whilst speaking of scientific discoveries as applied to practical 

 matters, I cannot leave unmentioned a process which, though ex- 

 tremely simple in itself, is likely to mark an era in the history of 

 the colony, and greatly to increase its wealth. I refer to the freez- 

 ing of meat, and other products which might perhaps be similarly 

 treated. I may mention, in passing, that the object of the process is 

 not, as might have been supposed, to change the temperature 

 of the atmosphere, but to suspend the vivifying powers of the 

 germs which are continually floating about in it. As Professor 

 Tyndall has pointed out, in his lecture before the Royal Institution 

 in 1877 and elsewhere, animal matter may remain uncorrupted for 

 months exposed to the air, provided that air is rendered perfectly 

 free from these germs ; whereas the slightest contact with air 

 in its ordinary impure state — a mere pin-hole in the vessel contain- 

 ing the clarified atmosphere, for instance — admits the germs, and 

 corruption ensues. The attempt to exclude the atmosphere from 

 meat during the passage to Europe has been made, and has been 

 found impracticable; but the desired result has been obtained by 

 chilling the air to such an extent that the vivifying power of these 

 germs is suspended. 



