23 



greater degree in ISSO than in 1S79. In fuct a eiini])arison of all of the wind 

 charts of 1880 with those of 1879 indicates a considerable degree of permanency 

 in the annual atmospheric movements. To Aicilitate this comparison, a series 

 of charts, niunliered 5a to 10a, have been prepared, showing results corresponding 

 to the foregoing, their construction having been based on the mean of the results 

 for 1879 and 1880. Tiie method of constructing the lirst diagram in chart 

 number 10 was e.-^plained in the last report. It shows the general course of the 

 wind during the year 1880 and it indicates a resultant movement of the atmos- 

 phere of 18000 miles from a direction North by about 4° East. Number 10a 

 shows a similar construction for the mean results of 1879 and 1880. It indicates 

 a mean annual movement of 14000 miles from a point North by 8° West. The 

 second diagram in chart number 10 consists of a curve showing the number of 

 miles of wind for each month of the year. It agrees very well in its general 

 features, with the corresponding curve for 1879 and in the second diagram of 

 chart number 10a the mean curve for the two years will be found. This exhibits 

 a great maximum in March and two other maxima, one in July and the other 

 in October. 



If these mean curves he continued from year to year as observations accu- 

 mulate, they will, in time, approximate very closely to a stability in form, and 

 it does not seem to be assuming too much to alfirm, upon the evidence of but 

 two years' observations, that this form will not diller greatly from that in which 

 they now appear. 



THE TYPHOON OF OCTOBER 3 AND 4. 



On the night of October 3 and 4 occurred a wind storm of extraordinary 

 violence, although, fortunately, of short duration. Indeed, so rapid were the 

 barometrical changes, that, coming as it did between two of the regular ob.serva- 

 tions, it may 1x3 said to have hardly left an iniiiicssiun ujinn the regular series. 

 Although without doubt the barometer reached the lowest point for the year at 

 that time, in the regular series the minimum is credited to Slarch 20 as is 

 previously stated. Fortunately Mr. Nobntivni, recognizing the unusual violence 

 of the storm, began making hourly observations of the barometer at 1 o'clock 

 a. m., afterwards increasing tlieir frequency to every half hour, ami continued 

 them until the following morning when the storm had entirely sub.sided. Tiio 

 anemograph furnishes a continuous record of the velocity of the wind and wo are 

 tlius able to trace, with tolerable completeness, the most important elements of 

 the phenomenon. The storm was by no mean« local as it is known to have 

 caused much damage along a considerable extent of the coast, and to have 

 brought about much disaster to shipping in the adjoining seas. In order to 

 undertake anything like a complete discussicjn of the phenomenon, it wouKl be 

 necessary to collect from numerous and widely distributed sources, all of the facts 



