56 Froceedings. 



November 8tli, 1886, at 6 p.m., there were seen eight belts 

 converging iu the N.N.W. and S.S.E. horizons; wind S. 

 There was a hinar halo later in the evening, after the belts 

 had disappeared. 



In all cases the belts followed the direction, or nearly the 

 direction, of the wind, and thus might well be said to lie 

 along the isobars. Weather varied in the different cases ; the 

 barometer and the wind also varied. Temperature, however, 

 showed similar conditions on each of the three occasions, viz., 

 a steady daily maximum, with a grass minimum regularly and 

 rapidly decreasing. Each occun-ence also took place between 

 two and three days before full moon. The lunar halo observed 

 on two of the three dates appears to have had no connection 

 with the phenomenon of the belts. 



These belts are described by Tromholt as " Polar bands"; 

 they occur at periods corresponding with the Auroral maxima, 

 and are, he says, by many attributed to the same cause. Mr. 

 Whipple, chief of the Kew Observatory, however, does not 

 admit their having any magnetic connections : he describes 

 them as "cuTofilum" clouds, or thread-cirrus, and says : — 

 " The phenomenon is not uncommon during unsettled weather. 

 The converging appearance of the lines is simply due to per- 

 spective, as the clouds themselves lie in parallel lines along 

 the isobars. They have no perceptible magnetic effect : how- 

 ever, I have had the magnetograph-curves for all three dates 

 submitted to my inspection, and find that in no case did they 

 indicate any movement of the needles. The cirrus-cloud, 

 which forms the 'Noah's Ark' cloud, being a mass of ice- 

 crystals, when sufficiently attenuated usually forms halos, as 

 you observed in two cases." 



It would seem that the first of the three occurrences differed 

 in some respects from the two others, viz., that it did not 

 occur in unsettled weather, and that the belts were not noted 

 as converging at the poles. 



Dr. Bossey then gave a demonstration, with the microscope, 

 "On the Structure of certain Ferns." 



