68 



The monthly weather diagram plainly shows that fog* was almost 

 entirely absent until the morning of the 18th. From then on to the 

 last of the month there was so much fog and bad visibility, however,, 

 that the figures for the whole month are slightly above what has; 

 here been called normal for the time and region. There were two 

 prolonged periods of fog, the first with a low barometer on the 18th, 

 19th, and 20th, and the second with comparatively high barometer 

 on the 27th, 28th, 29th, and 30th. The latter period of thick weather 

 was terminated on the 30th by a shift of wind to the westward which 

 followed upon the passage, far to the north through the Strait of 

 Belle Isle, of the center of a large cyclonic storm. 



Throughout nine half-day periods the wind force averaged Beaufort 

 7 or greater. This shows more boisterous conditions than obtained 

 during April, 1928, for then only five such periods were recorded. 

 During two of the cyclonic disturbances very heavy swells were noted 

 with waves at least 30 feet high. This height was estimated by noting 

 when the ship was on an even keel in the trough between swells the 

 height above the water line at which the line of sight ran off tangent 

 to the tops of the seas. 



When over the cold water, even during the periods of good visi- 

 bility, morning and evening star sights could very seldom be obtained 

 because of a typical stratus cloud formation, resembling a high fog, 

 that was very frec^uently noted at certain hours. It was dark and 

 heavy early in the morning, but gradually thinned out during the 

 course of the forenoon. Around 10 a. m. a pale sun could be seen 

 through the thinner parts, and at this time the first observations of 

 the day could be taken, usually without the use of any shade glasses 

 in the sextants. From about 11a. m. to 3 p. m. sun sights could 

 usually be taken at will, but as the afternoon progressed the rolling, 

 fairly low, cloud layer would form again, blot out the blue sky, and 

 gradually thicken until the sun's disk could be seen no more. This 

 sort of cloudiness did not hamper the search for ice greatly, for the 

 visibility usually remained excellent just over the sea, the lower limits^ 

 of the fog or cloud keeping at a uniform moderate level at all times. 

 The delay in fixing position was the most serious thing involved, 

 preventing as it did prompt and accurate determination of ship's- 

 position, berg drifts, currents, and exact limits of areas fully searched. 



MAY 



Maximum air temperature, 56° F. 

 Minimum air temperature, 34° F. 

 Average air temperature, 42.9° F. 



Visibility was less than 4 miles 34 per cent of the time. 

 Visibility was less than 2 miles 27 per cent of the time. 

 May, 1928, had about twice as much fog and bad visibility, as 

 usual, but in 1929 the figures for the month were back to normal again. 



