Q FREER. 



and March do not show as high a figure as the comparatively 

 cloudy ones of June and July. 



Kuala Lumpur (Table II) shows a slightly higher average, 

 15.29 as against 12.45, but its maximum is somewhat higher 

 (18.1 against 17.8) and its minimum much higher, namely 9.0 

 as against 1.15 for Manila. In other words, the insolation in 

 regard to the rays under discussion in Kuala Lumpur on average 

 clear days is practically the same as in Manila, but the cloudy 

 and hazy weather of our island climate shuts off such a pro- 

 portion of the sunlight that the total effect is that of a climate 

 having less insolation; in other words, the difference between 

 two places, one practically on the equator and the other 14° 

 north is a meteorological one, and not due to any excess per se 

 of the shorter wave lengths in the former. 



Honolulu (Table III) shows an average of 13.81, or 1.36 higher 

 than Manila and only 1.48 lower than Kuala Lumpur. It had 

 an abnormal maximum in September, 1911, of 20.77, or higher 

 than either of the so-called tropical places and a minimum of 3.48. 

 However, the average of days above the average mean is 15.82 

 as against 16.52 for Kuala Lumpur. No months in Honolulu 

 are as low as the lowest in Manila (September, December; 10.94 

 and 10.03 respectively). Therefore, Honolulu (21° 18' north) 

 has, as regards the photocatalytic action of the sun's rays, a 

 climate much hke that of Manila (14° 36' north) and Kuala 

 Lumpur (3° 10' north), and the extraordinarily high days ob- 

 served at that place indicate that at times the atmosphere on 

 Hawaii is so free from disturbances, strata of varying density, 

 or haze, as to allow even a greater proportion of the rays having 

 photocatalytic action to reach the surface of the earth, than is 

 the case in the more southern places. No one will venture to 

 state that the sunlight is more oppressive in Honolulu than in 

 the Philippines; indeed, the general temperature is lower, the 

 average temperature at the time of the observation was 21°. 1 

 to 22°. 6, where ours in Manila was 30° to 35°, so that, if the 

 slight temperature coefficient for the differences were to be 

 taken into consideration, Honolulu ^« would result even higher. 

 The difference between these three places under discussion is 



"The figures from Honolulu are not final as the flask used was a 200- 

 cubic-centimeter Jena glass Erlenmeyer and has not yet reached us for 

 standardization. This will probably make the rate high, but, on the other 

 hand, our standard is a quartz flask, which would offset the increase due 

 to greater surface in the Honolulu flask, so that probably but little cor- 

 rection will be necessary in the end. 



