NO. 4 



SITE FOR SOLAR-RADIATION STATION — MOORE 



19 



and satisfactory days totaled nearly 95 per cent, while there were 

 84 per cent of days of calm or light wind. During June, however, the 

 wind was rated as moderate or brisk on over half of the days. No 

 days were lost by clouds in either June or July. 



From the above it is seen that during the four months of March, 

 April, May, and June, the chief drawback in the weather conditions 

 on Mount St. Katherine was the haziness. Only six days out of a 

 total of 106 were lost by clouds, which is a very admirable record, 



LOG /^ 



^sc 



3 8 13 



L06 PYRHELIOMETER SOLAR CALORIES 



Fig. 8. 



particularly for spring months. And the prevailing calmness is a 

 strong point in favor of the place, especially as compared with South- 

 west Africa, where the wind was found to be a very serious handicap 

 to accurate observations. We made inquiry regarding summer thunder- 

 storms and from all sources learned that they are exceedingly rare. 

 Lightning does occasionally accompany winter storms, but the absence 

 of marks made by lightning on the rocks of the high peaks in Sinai is 

 in great contrast to such peaks in Southwest Africa, where the rocks 

 are literally covered with the markings. 



