22.2 DEPARTME'NT OF THE NiVAK SERVICE 



principles, in particular the Archimedean, which, in addition to being generally 

 understood, is simple and easily comprehensible in itself. I have, moreover, in order 

 to exemplify these principles, given reports of some experiments and also taken some 

 examples from the atmosphere when the hydrographical facts were insufficient. 

 Such limitation and simplification will, 1 trust, render these complicated yet 

 interesting theories accessible to a wider circle among those at all occupied with 

 marine phenomena. 



The following pages open with a short report of Dr. Hjort's observations. These 

 naturally form the foundation upon which the whole of the subsequent dis- 

 cussion is based, as without knowledge of the conditions prevailing down in deep 

 water, it would be impossible to explain the phenomena which take place in the sea, 

 or even those apparent at the surface. The next sections will be devoted to ray own 

 explanation of the questions concerned, in the simplified manner above mentioned, 

 leading up to an exposition of that part of Bjerknes' theory which directly applies to 

 conditions in the sea, further the changes into different kinds of the energy in the 

 sea and as summary an application of the laws found on the Canadian Atlantic 

 waters. 



I.— GEOGEAPHICAL CONDITIONS OF THE AEEA OF INVESTIGATION. 



I have before me a chart of the area in question, with numerous soundings, pre- 

 senting a detailed survey of the bathymetrical conditions. In order to obtain some idea 

 as to the dimensions of this marine basin, I draw out on the chart a system of parallel 

 lines, at intervals of 100 km., each line being again divided up into lengths of 100 km., 

 (fig. 1). At the points thus marked off, I draw short lines indicating the depth, these 

 latter being perpendicular to the original system of parallels. By inserting the inter- 

 mediate depths according to the chart, vertical sections are obtained for every 100 km. 

 throughout the entire area. (Fig. 1.) 



In marking off the depths, I endeavoured at first to adhere to the same scale as 

 that for the horizontal dimensions of the chart, but found the lines thus drawn too 

 short ; I therefore multiplied them by ten, so that the lines for vertical dimension were 

 drawn to a scale ten times that of the horizontal. Even this, however, proved insuffi- 

 cient, and I found it necessary to magnify them 100 times in order to render them 

 reasonably legible. 



In order, then, to' obtain a correct idea as to the bathymetrical conditions within 

 the area investigated, we must imagine the depth lines reduced to one-hundredth of 

 the length shown in the figure. It now becomes apparent, that the vertical dimensions 

 are extremely small in comparison with the horizontal. Drawn to the scale of the 

 chart, the greatest depth within the area would appear about equal to the thickness of 

 the paper on which it is printed. And if we should attempt to draw a vertical section 

 across the area, maintaining the correct proportion between depth and horizontal 

 extent, the result would be merely a line and this moreover in the shallower portions, 

 so fine as to be invisible to the eye. 



If we were to make an exact model, on a reduced scale, of the area in question, it 

 would appear, at a first glance, to be perfectly flat. And on attempting to " fill " it 

 with water to a level answering to that of the sea, as a first step to experimental repro- 

 duction of the actual hydrographical phenomena, even this would be found practically 

 impossible, owing to the surface tension of the water. So thin a layer would either 

 wet the entire surface of the model or leave dry patches here and there without regard 

 to level. To obtain a basin suitable for the purposes of such experiment, the depth 

 would have to be magnified 1,000 times in proportion to the horizontal extent. 



This disproportion between the vertical and horizontal dimensions should be con- 

 stantly borne in mind throughout the discussion of tlx sections dealt with in the fol- 

 lowing pages. 



