170 SCHOOL SCIENCE AND MATHEMATICS

Nor should all snakes be exterminated. Rather it should beemphasized that a large proportion of both our harmless andpoisonous snakes are distinctly beneficial. The Blue Racer,supposedly possessed of unbelievable speed and agility, andindeed thought by many to be poisonous, has a distinct economicvalue to the farmer, and thus to all of us. A large proportion ofhis food consists of grasshoppers, field mice, and other animalsthat are injurious to men. And so with the Bull Snake, the so-called Chicken Snake, the Whip Snake and many other entirelyharmless varieties; their food habits make them deserving of theprotection of man. Even the much-hated Rattlesnake has some-thing in his favor, for he lives largely on the very destructivesmall rodents.The only treatment for a poisonous snake bite that is of much

avail is the injection of the serum which is specific for that kindof snake. There is a wide difference in the venoms of the twomajor groups of poisonous snakes�the Pit Vipers and theCobras. Regarding the types of venoms and the specific meth-ods of treatment more will be said in a later article.

THE LEANING TOWER OF PISA.

BY W. P. SCHAPHOBST, M. 30.,/ Neioark, N. J.Not long ago I saw a very interesting photograph of engineering equip-

ment installed in the vicinity of the Leaning Tower of Pisa. Engineersare now "fixing" the foundation. I endeavored to obtain a copy of tlicphotograph for use in connection with this article, but the contractorcould not give one to me because, he said, it was the property of a Euro-pean concern.

Air compressors and much cement were in evidence in the photograph.These compressors are used for pumping air and liquid cement throughtunnels beneath Pisa to solidify the foundation under and around theleaning tower, making falling an impossibility. The engineers are diggingpits around the tower and are drilling openings toward the foundationand directly beneath it and are pumping those openings full of high gradecement.

In other words a comparatively small amount of earth is removed frombeneath the tower and as rapidly as it is removed it is replaced with ce-ment. Eventually, therefore, there will be no earth directly beneathPisa. It will be standing on solid cement and when completed there willbe no possibility whatever that Pisa will ever fall over due to loss of equi-librium. During recent years the world has become alarmed over therapidly increasing rate of inclination of the tower. The greater the leanthe greater the pressure on the "toe" or lowest edge of the tower’s founda-tion. As soon as the toe rests on a sufficient area of solid cement or con-crete, there will be no more settling. Pisa will continue to lean for manycenturies to come.