144 Trans. Acad. Sci. of iSt. Louis. 



which occurred in France on Jan. 24, 1879, where some 50% 

 of the wood was broken. He states among other things that 

 a branch of Rhododendron weighing 13 grams bore a load of 

 360 grams of ice, and that an oak 2 meters in circumference 

 was bent to within 4 m. of the ground. Plowright * tells of 

 a similar storm which swept over portions of England on Jan. 

 7th, 1889. He figures an oak tree showing broken branches. 



The storm of Feb. 27th began late in the afternoon. The 

 maximum afternoon temperature was 29.2° F. Towards even- 

 ing the temperature fell to 27.2° F. at 7 p. m. and reached a 

 minimum of 26.6° F. during the night. The rainfall of Feb. 

 27th up to 7 o'clock was .36 inch. During the night 1.07 

 inches fell. About 8 o'clock it began to rain: the water 

 froze as soon as it fell, and by the next morning a heavy 

 coating of ice covered the trees, which were bent to the 

 ground in many places by the load. The temperature of 

 Feb. 28th remained below freezing ( min.24.2° F., max. 30° F. ), 

 likewise on the succeeding days,t and not until March 4th did 

 any of the ice melt. By March 6th it had all disappeared. 



The destruction brought about by the ice was very great, 

 but considering the enormous weight which rested upon the 

 branches, it is astonishing that it was not greater. The 

 downward pressure exerted by the ice is oftentimes but one 

 of the factors which cause a branch or trunk to break. The 

 wind is of as great importance if not more so. A branch 

 heavily weighted will bend far from its normal position with- 

 out breaking, but if it is swayed back and forth violently the 

 chances that it will break are almost doubled. Branches are 

 very much more brittle when frozen, and a blow which would 

 not affect a branch ordinarily will cause it to snap off when 

 frozen, particularly if weighted with ice. Thus it is, that 



* Plowright, C. B. Notes on Hoar Frost. Jour. Roy. Hort. Soc. 

 13 : 117. 1891 ; also Gardener's Chronicle III. 5 : 459. 1889. 

 t The temperatures were : — 



Max. Min. Max. Min. 



March 1 33° 26° March 4 52° 35° 



2 34° 27° 5 58° 34° 



3 40° 29° 6 60° 28° 



The writer is indebted to Dr. R. J. Hyatt of the St. Louis Weather Bureau 

 for the meteorological data. 



