2(]C) PROGRESS OF METEOROLOGY IN 1889. 



(3) A deeper layer, more densely filled witb tniniite and also with 

 still larger particles sufiices to explain the phenomena of 1883-'84. 



(4) The dnst and haze needed to produce red coloration of light by 

 selective absorption and reflection is always present in the lowest air 

 stratum. 



(5) The Krakatoa eruption sufficed to throw sufficient moisture into 

 the atmosphere to explain the diffractive phenomena of 1883-'84 and 

 its gradual subsidence since then. 



(6) The daily weather reports printed in the Signal Service Bull. Int. 

 Sitmd. Ohs. shows that the distribution of Krakatoa vapor must have 

 been largely influenced by disturbances in the lower atmosphere, and 

 we do not need to assume an exclusive influence of general upper cur- 

 rents, either easterly or westerly. {Am. Meteor. Journal, v, p. 529.) 



Mr. S. E. Bishop, in a letter dated Honolulu, July 25, 1889, reports a 

 re appearance, beginning on July 13, of sunset glows like those of 1883- 

 '84, but of less brilliancy. The glows were brightest on the 14th and 

 the 15th and were visible until the 20th, with decreasing intensity. A 

 space of 15° radius around the sun was occupied by a whitish glow, 

 like that in " Bishop's Ring." A noticeable peculiarity of the present 

 glows is the occurrence of a tertiary glow in addition to the primary and 

 secondary. Another difference is the much earlier time at which the 

 glows take place, and the rapidity with which they follow each other, 

 indicating that the reflecting stratum of haze is very low down as com- 

 pared with the Krakatoa haze. The reflected rays of the sun, travers- 

 ing a smaller extent of the lower atmospliere, show less red, having less 

 of the other colors interrupted. For the same reason they retain force 

 enough for a third reflection, in which a very pure, though faint, red ap- 

 pears. {Nature, XL, p. 415.) 



Mr. J. W. Backhouse reports a feeble re-appearance over western 

 Euroi)eof a great corona around the sun during August and Septem- 

 ber, 1889. {Nature, XL, p. 519.) 



Noctilucous clouds. — O. Jesse gives the following discription of the 

 luminous night clouds that have been visible in Europe during the 

 months of June and July since 1885. They are visible only in that por- 

 tion of the evening or morning sky which is illuminated by the twilight 

 and bounded by the twilight arc. These clouds disappear as soon as 

 the twilight arc passes over them. In the evening the clouds appear 

 when the sun is about 10° below the horizon, and continue visible 

 throughout the duration of twilight. In the morning the phenomena 

 are inverted. They are very similar to cirri in form and structure, but 

 when an ordinary cirrus cloud is present it looks much darker than the 

 twilight sky surrounding it, while luminous clouds are brighter. {Me- 

 teorologisclie Zeitschrift, 1889, vi, p. 184.) 



Prof. John LeConte discusses in Nature the origin and source of the 

 light in noctilucous clouds, and refers to a collection of observations of 

 this phenomenon made by Arago, and to his conclusion that the clouds 

 are self luminous. Professor Le Conte has observed on the coast of 



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