540 Scientific Proceedings, Royal Dublin Society. 



Mr. B. Bunnemeyer, Meteorologist. Of special interest are the oblique arcs 

 of the anthelion marked ' g,' which are shown to meet in the upper part of 

 the 22° halo. 



"A perfect solar halo was observed at Houston, Tex., at 11.30 a.m., 

 October 3rd, 1917, consisting of — (a) a halo of 22° radius; (b) an elliptical 

 circumscribed halo; (c) arcs of a halo of 45°; (d) supralateral arc tangent 

 to halo of 45° ; (e) infralateral arcs tangent to halo of 45° ; (/) parhelic circle 

 of approximately 35° radius with zenith as centre ; and (g) oblique arcs of 

 the anthelion touching the halo of 22°. The halo was at its best when first 

 observed. The accompanying sketch [PI. L., fig. 1] of the phenomenon was 

 prepared by Mr. I. E Tannehill, assistant observer. [Additional inquiry of 

 the Houston office force confirms the correctness of this point in the sketch 

 here published as fig. 1. — C. A. jun.] 



"There were no parhelia. The parhelic circle (/) and the oblique arcs 

 of the anthelion (g) were white ; all other circles or arcs of circles exhibited 

 the colours of the rainbow, with the red colour towards the sun. The display 

 was indescribably beautiful, and caused general comment and numerous 

 inquiries as to its significance. The day was perfect, with an average 

 cloudiness of only 3/10. Cirrus and cirro-stratus clouds surrounded the sun, 

 intermingled with a very few cirro-cumulus. Here and there a few small 

 cumulus clouds drifted across the sky. A faint cirrus haze was also observed. 

 The parhelic circle and oblique arcs of the anthelion seemed to be projected 

 for a large part upon a clear sky. The northern portion of the circumference 

 of the halo of 22° and of the elliptical circumscribed halo were superimposed 

 for a distance of about 40°, and the southern for a distance of perhaps 12°. 



" The phenomenon began to dissolve slowly toward noon, and by 2.30 p.m. 

 the last traces had faded away. For twelve days preceding its appearance, 

 and for four days following it, the weather was perfect, with mostly clear 

 sky. 



" The time used was that of the 90th meridian." 



" Gallia, Ohio. — Solar halo-phenomena were also observed on this date 

 by Mr. J. S. Houser, Associate Entomologist of the Ohio Agricultural 

 Experiment Station. His description and sketch (PI. L., fig. 2) follow: — 



" I am enclosing a sketch of parhelia re-drawn from a field-sketch made 

 at Gallia, Ohio, October 3rd, 1917, at 2.30 in the afternoon. 



"Perhaps such phenomena are quite common to you, but they were 

 decidedly unusual to me. The semicircular bands of light A and B, while 

 indistinct, were continuous ; and the intensified patches of light C, D, E, F, G, 

 H, I, and J, appeared with varying degrees of distinctness. Patch C was 



