xviii Proceedings, &c. 



the observations made by himself at the Melbourne Observatory, 

 showed the differences which existed between the true temperature 

 of the dew point as ascertained by direct experiment, and as obtained 

 by the formula and the factors applied to the indications of the dry 

 and wet bulb thermometers. These exhibited some remarkable dis- 

 crepancies. Mr. Smyth recommended that in every country where 

 there is a fixed observatoiy, it should be the first duty of the director 

 to commence a system of daily observations with good standard Kew 

 thermometers, and the best construction of hygrometer, with the 

 view of accumulating data from which useful factors could be de- 

 duced ; and he expressed the opinion that observations, extending 

 over lengthened periods, from many observatories, would give, in all 

 probability, factors grouped in such a manner as to be useful in eveiy 

 part of the world. He gave the results of some experiments which 

 he had made to determine the effect of currents of air on the wet 

 bulb, and expressed himself satisfied with the sufficiency of Mr. 

 Glaister's theory. He concluded by exhibiting an instrument for 

 ascertaining the dew point, after his own design,' manufactured by 

 Mr. Edwin Jones, of Collins-street east. It consisted of two cups 

 containing cold and relatively warm water, respectively emptying 

 through pipes into a third cup (of thin gold), in which the bulb of 

 a Kew thermometer was immersed. Mr. Smyth explained that this 

 was oidy a modification of an old and well-known principle, but he 

 believed the mechanical arrangements which he had obtained, and 

 the substitution of a large Kew thermometer for the small one gene- 

 rally used, would afford accurate results. 



Mr. Smyth replied to some questions put by the members. 



The Institute then separated. 



18th August, 1858. 



Ordinary Meeting. 



Sir W. F. Stawell, President, in the Chair. 



His Excellency the Governor was present. 



The reading of the minutes of the previous ordinary meeting was 

 postponed, because of the unavoidable absence, during the early 

 part of the evening, of the secretary, Dr. Macadam. 



Eecently elected members were introduced to the Institute. 

 The following gentlemen were elected ordinary members, by ballot, 

 Dr. Gillbee and R. B. Smyth, Esq., acting as scrutineers : — 

 William Perry, Esq., Melbourne. 

 William Swan Urquhart, Esq., Tarradale. 

 William Robertson, Esq., Wooling, near Gisborne. 

 David Blair, Esq., M.L.A., Melbourne. 

 David Wilkinson, Esq., C.E., Prahran. 

 Edmund Sasse, Esq., Geelong. 



