166 MICHIGAN ACADEMY OF SCIENCE. 



MAGNIOTIC PHENOMENA AROUND DEEP BORINGS. 



BY A. C. LAXE, STATE GEOLOGIST. 



• 



In an early paper by Prof. Alexander Winchell he calls attention to 

 magnetic phenomena around certain springs in the State, but without 

 specifying })recisely what these phenomena were. It is also noteworthy 

 that a large number of the springs or rather artesian wells, that have 

 been exploited as mineral waters, have "magnetic" in their name* or like 

 the St. Louis s]»ring make reference in their circulars to their magnetic 

 powers as of great value. In the course of my studies on the water 

 supply of Michigan, and in the examination of other borings of various 

 kinds, which is part of my regular business, it became a matter of some 

 interest to know just what these magnetic phenomena were. So far as I 

 could find out they were of two kinds. All the wells in question are 

 drilled wells in iron casing, and even when this casing was said to be 

 wrought or soft iron it had a considerable attraction. It would for in- 

 stance hold out nails, and the pull upon a wrench could very 

 readily be felt. Sometimes too, it was noticed that the blade of a 

 knife immersed in the water also became magnetic. Of this last state- 

 ment I may remark that while it is very easy for knife blades to have 

 become magnetic without the owner's knowledge yet there is no reason 

 to doubt that in some cases knife blades did really become magnetic. 

 However, I do not know of any case where the knife blade became magnetic 

 except as it was held in the water as it flowed from the casing, and hence 

 close to the latter. Now any knife blade being steel if it is held close to a 

 magnet will soon become permanently magnetized itself, so that the two 

 phenomena reduce themselves to one, mainly the magnetism of the casing. 

 As to any well defined magnetic effects of the waters of a medical nature 

 I am not qualified to judge, not being a physician, nor have I had them 

 stated to me in any tangible state. Now in regard to the casing, we must 

 remember that the earth as a whole is a magnet and electro-magnetic cur- 

 rents are continually flowing in it, and that any iron rod or tube lying^ 

 in a magnetic field and cutting the lines of force will itself be magnetized, 

 just as a soft iron nail touching or close to a magnet will itself become 

 attractive and be able to draw a smaller nail. Applying this to the case 

 of these deep wells we have continuous lines of iron pipes, of wrought 

 iron or steel (and sometimes pipe that is sold for wrought iron is really 

 steel), which may vai-y in length from a hundred feet to two or three 

 thousand or more and it is not surprising Ihat they sliould be magnetic 

 as they cut a good many lines of force of the great earth magnet. These 

 lines are rei)rest^nted in a horizontal direction by the compass and in a 

 vertical i)lane by the dip needle. If this explanation of the magnetism 

 is correct, then all strings of casing should i)rove to be more or less 

 magnetic. Such indeed I have found to be the case very often to the 

 considerable surprise of the owners thereof, though well drillers tell me 



* Such iis Midland Magnetic. Grand Riipids Magnetic, Riverside Matrneiic at Detroit, and Magnetic 

 Springs at Leslie, Lansing, Fruitport and Huboardsion, the analyses of which are given in Water 

 Supply Paper No. 31 of the U. S Geolosjical Survey. 



