290 DEPARTMENT OF THE XATAL HERVICE 



Gradually, owing to rainfall, inflow of river water, melting of ice, etc., the water 

 of the cushion becomes somewhat lighter than that of the Gaspe current, and is thus 

 better able to resist the southAvard pressure of the current itself. 



In Cabot strait, the continuation of the Gaspe current keeps close in to cape 

 North, C. Breton island, owing to the earth's rotation. With a strong easterly wind, 

 the whole of this current will be stopped, and all its water stored up in the cushion 

 in the southern part of the gulf of St. Lawrence. The cushion is thereby increased 

 both in depth and horizontal extent, and consequently, the solenoids in the gulf of 

 St. Lawrence, which drive the Gaspe water forward, become stronger in turn. If the 

 east wind keeps up for any length of time, this solenoid system will at last become 

 so strong as to drive the Gaspe water past cape North, despite the wind against it. 

 When the east wind drops, the current will be stronger than normal for a time, as it 

 will then, in addition to the Gaspe water, also have to carry out the superfluous water 

 of the cushion. 



With a southwesterly wind, on the other hand, the water of the cushion will be 

 driven out through Cabot strait. The current is thus increased at first, but when the 

 water in the cushion has sufficiently diminished the current past cape North will once 

 more become normal, despite the southwesterly wind. When the southwesterly wind 

 ceases, the current will grow weaker, as a great part of the Gaspe water will then go 

 to form a new cushion. In a word, the effect of this accumulated mass of water may 

 be popularly described as similar to that of the air in the bag of a Scottish bagpipe. 



The principal portion of the Gaspe water is naturally formed outside the mouth 

 of the St. Lawrence river, but the current also absorbs a considerable amount of water 

 from its surroundings throughout its course, by friction against the subjacent layer, 

 and by diffusion. Consequently, the farther it proceeds, the more it increases in 

 volume and salinity and the more it grows to resemble the water around it. On the 

 coast of Nova Scotia, and even more in the gulf of Maine, it differs but slightly from 

 its surroundings, and a storm will here suffice to mix it up completely with the adja- 

 cent water. Thus far at least, however, the water of the St. Lawrence river flows 

 before losing its individuality and becoming finally intermingled with the ocean. 



We now come to the most remarkable feature in the hydrography and hydro- 

 dynamics of the Canadian Atlantic area, viz., the cold intermediate layer. From 

 plates IV and V it will be seen that this is of very great extent, and that it is largely 

 restricted to a constant level. It is a result of the melting of ice in the gulf of St. 

 Lawrence, and partly, also in all probability, in the Arctic ocean. From the section 

 east of cape Ray, it would seem that this layer forms an important intermediate or 

 lower portion of the Labrador current. Its movement, together with this latter, is 

 unmistakable. The cold water presses against the banks and the coast, as a result of 

 the earth's rotation, which forces it towards the right. 



It is thus likely that the greater portion of this water is produced farther to the 

 north, in the Greenland waters. Its thickness decreasing to the southward, we conse- 

 quently find, in the cold layer itself, solenoids which force it towards this point of the 

 compass. On reaching Cabot strait, it is forced by the earth's rotation into the gulf 

 of St. Lawrence, and fills it to the level where it belongs by virtue of its specific 

 gravity. From the gulf of St. Lawrence it pours out via cape North along the coast 

 of Nova Scotia or rounding Banquereau. These outward currents are considerably 

 stronger in spring than in summer, owing to the melting of the ice in the gulf during 

 the former season. A peculiar phenomenon may be noted in connection with these. 

 The screwing movement of the ocean current presses the cold subjacent water out 

 from the shore, vide plates IV and V, where, owing to friction against the water 

 above, it probably rotates in an opposite direction to the latter, exactly as two cog- 

 wheels in contact move opposite ways. In this manner, the cold water mass acquires 

 its rotmded form, as shown in fig. 60. 



