THE PARTIAL SOLAR FXLIPSE. APRIL 17th. 1912. 



Bv E. \\'. HARLOW. F.K.A.S. 



This phenomenon was observed at Bournemouth, where the 

 extent of obscuration was between 91 A percent, and 9 J per 

 cent., under e.xcellent conditions, the sky being throughout 

 absohitely cloudless and the definition good. 



liilit.iined uitli my usual arranj;ement (4i;-inch refracting 



mid-eclipse a heavy gloom like that of a thunderstorm 

 pervaded. (Outside the sunlight was very feeble and some- 

 what ruddy, the sky of a very deep leaden blue and all colours 

 much toned down as if degraded with black. .\t 11.43 ;uni., 

 about twenty-live minutes before mid-eclipse, a sm.ill cumulus 



jl:ir Kchp 



t |,h. 



p.m. 



telescope with camera and yellow colour filters affixed) a fine 

 series of twenty-four negatives of all phases of the eclipse. 

 The accompanying one was taken at 12-5 p.m. Greenwich 

 time. I do not know exactly when the maximum obscuration 

 occurred here, but this photograph was secured at not more 

 than two minutes' inter\al of time from mid-eclipse. 



It is enlarged, the original image being about 2i inches in 

 diameter. 



The solar disc was absolutely free from markings of any 

 kind, spots or faculae. 



The irregularity of the lunar limb is well shown ; there are 

 two distinct peaks visible on this (and several other of the 

 negatives' about one-third of the way round the arc of the 

 lunar limb from the right hand I Nicest) side. 



The diminution of the sun's light was very marked indeed 

 and the eclipse proved a noteworthy spectacle. Indoors at 



cloud which appeared on the X.W. horizon had a distinct 

 coppery shade. 



About eight minutes after mid-eclipse, on disconnecting the 

 camera and substituting a Thorp polarising solar diagonal, I 

 clearly perceived, for some considerable distance beyond each 

 cusp, the portion of the lunar limb outside the sun's disc — ^in 

 other words, the projection of the moon on the corona. This 

 was also observed, to a less extent, with a three-inch refractor, 

 ordinary solar diagonal and green cap, a few minutes later. 



The temperature in the sun on the grass fell from 

 yrp. at the beginning to 55° at 12.14 p.m., about seven 

 minutes after mid-eclipse, and rose to 90° by 1.30 p.m.. 

 the end of the eclipse— a drop of 36°. These observations 

 were made with an ordinary thermometer, the bulb of which 

 was surrounded by metal bars to hold it in place. The fall 

 recorded is very nearly equal to that obtained with the 



