FRIENDL Y INSECTS. 171 



orce required to do the observed damage, and has considered this as the maxi- 

 mum force of the wind, although, of course, it may have been much higher. 

 Some of the hurricanes were very destructive, the one at Marshfield having cut 

 down everything along a path 46 miles long and 1,800 feet wide, killing 250 peo- 

 ple. Mr. Smith has formed the conclusion that notwithstanding these examples, 

 30 lb. square foot is sufficient wind pressure to allow for in a working specifica- 

 tion. As reasons for this conclusion, Mr. Smith expresses doubts as to whether 

 a direct wind or gale ever exceeds this pressure. Whirlwinds may exceed it, but 

 the width of the pathway of maximum effort in these is usually very narrow. Mr. 

 Smith has only found one example, already quoted, wherein the path of pressures 

 over 30 lb. per square foot exceeded 60 feet wide. This pressure is in itself very 

 unusual, and, referring more particularly to railway bridges, it is stated that a 

 loaded passenger train will leave the rails at this pressure of wind, and conse- 

 quently not much could be gained by making the bridge strong enough to resist 

 a storm which would blow a train off \\..— Scientific American. 



ENTOMOLOGY. 



FRIENDLY INSECTS. 



PROF. F. H. SNOW, KANSAS STATE UNIVERSITY. 

 \^Abstract of Lecture delivered before the Douglas County Horticultural Society."] 



He said in substance, that it was generally believed that insects were a nui- 

 sance and a curse in the world, but the study of botany and entomology proves 

 quite the contrary. The Professor made the broad statement that if all insect 

 life could be obliterated from the world, vegetation would deteriorate, and finally 

 die out, leaving the animal kingdom to perish for lack of sustenance, and then 

 proceeded by help of his botanical drawings and the extensive cabinet of insects 

 to prove the proposition. 



Almost every tree has its species of insects which feed upon it, and in many 

 cases destroy it. As a rule they feed upon the weaker specimens, thus thinning 

 out the forest, and allowing the remaining trees to grow larger and more perfect. 

 In artificial groves and plantations this necessity does not exist, and then it be- 

 comes necessary to employ agencies to prevent this destruction.. 



Cross-fertilization is one of the most useful and important employments of in- 

 sect life. The stamens of many plants, which have both fertilizing organs per- 

 fect, are not ready to discharge the pollen when the pistils of the same plant are 

 in the proper stage to receive it, hence the fertilizing dust must be conveyed from 



