Proceedings of the Polytechnic Association. 971 



Dr. P. II. Yaiiderweyde said, one of the benefits of tliis association 

 is, tliat a discussion is always in oi-der after a tlieory is broached. 

 Mr. Maury says, tliat tlie gulf stream takes its orio-in from the' coast 

 of Africa. IIow can so large a stream take its course from there ? 

 Its real oi'igin is the Pacific ocean ; further back than the coast of 

 Africa. The Indian ocean is a portion of tlie Pacific. (The Dr. 

 further illustrated tliis point h\ tracing the course of the gulf stream 

 on the maps.) The theory of Ilerschel is, that water like the gulf 

 stream must seem l»lne, for the reason that tlie sky is blue. Any 

 transparent matter that luis no color must look l»lue. When a diver 

 looks through water the color looks red. In the Mississippi river 

 there is so much sediment we cannot see the blue. The waters of 

 Xiagara and Lake Erie are blue, and it is blue in mid-ocean. As to 

 the rainfall, some three feet of water is cai-ried up from this river 

 ever year; but we must recollect tluit it rains as much down again, 

 Mr. MauiT, also states that the heaviest water on the globe is found in 

 the gulf of Mexico ; now we know tliat the water of Salt lake and the 

 Dead sea are much heavier, but it may be that Mr. Maury refers to sea 

 water. The water at the poles is heavy because it is cold, and the gulf 

 stream water being warmer and lighter, flows on the top. It is very 

 evident that the clinuite of England, Ireland, and Scotland, and 

 other i^irts of Europe is much clianged by the gulf stream. These 

 countries Avould not be what tliey are were it not for this stream ; so 

 is the climate of Calitbi'uia modified, and for the same reason. But 

 we must not ovei'rate the amount of heat carried over by the gulf 

 stream ; all tl|klieat of this stream does not go out of it ; it will give 

 its heat according to the laws of connection. We must take into 

 account that water 'possesses the most s])ecific heat of anybody in 

 nature, so in that respect the gulf stream is very powerful. As to 

 calling the Atlantic ocean a canal he objected U) that term, if com- 

 pared with its widtl), it is a very small canal, it is rather a plateau. 

 1'lie whole amount of water-vapoi- that the atmosphere can contain 

 at the same time is very little, suppose the whole atniosj)liere was 

 saturated with water, and it came down all at once, the surface of the 

 ocean would be raised only four inches ! 



Professor Phin stated that the greatest evaporation of the ocean 

 known is in the Indian ocean, tht; nuuisoon regions. The annual 

 evapoi-atiou is some eighteen feet. The average amount of rainfall 

 is aliont five feet. Keith Johnson, it his atlas, says that tluj annual 

 fall of rain on the surface of the glolje is five feet. Colonel Sykea 



