490 



SCIENCE 



[N. S. Vol. XLH. No. 1084 



needs not only to be intelligent on game if lie 

 is to execute the laws properly, but lie needs 

 furthermore to know the influence of game 

 and fur-bearing animals upon forests. 



Curator W. C. Mills, of the Ohio Archeo- 

 logical and Historical Society, and also of the 

 Archeological Museum of the Ohio State Uni- 

 versity, has this summer been excavating a 

 mound situated on the farm of State Senator 

 W. D. Tremper. It has yielded hundreds of 

 valuable specimens, which show remarkable 

 skill in the art of graving and carving. In 

 addition, there is evidence that here in this 

 mound communal or tribal relations existed, 

 for instead of numerous individual graves, one 

 common grave served for the receptacle for 

 hundreds of bodies. There are many other 

 characteristics, which make this mound stand 

 out. For instance, it was found that a wooden 

 palisade had been erected around it. It was 

 also discovered that the builders worked in 

 quartz and several specimens were obtained. 

 The Tremper mound is in form that of an 

 animal enclosed by an embankment or wall. 

 It is 250 feet long, with an average width of 

 50 feet and a maximum height of 84 feet. Be- 

 cause of its resemblance to an animal it early 

 became known as the Elephant Mound, al- 

 though recent exploration has proved this for- 

 mation to be incident to its use and construc- 

 tion and not intended to represent an animal. 



Probably the most accurate method for the 

 determination of the value of the strength of 

 an electrical current in absolute measure is 

 by means of the Eayleigh current balance, in 

 which the current to be measured is passed in 

 series through two parallel circular coils of un- 

 equal radii, one of which is suspended from the 

 beam of a balance. The distance between the 

 planes of the coils is varied until the force of 

 attraction between the two coils is a maximum, 

 and the value of the force is obtained by add- 

 ing weights to the other arm of the balance 

 until its equilibrium is restored. Since the 

 maximum force obtainable depends on the 

 ratio of the radii of the coils alone, and not 

 on their individual dimensions, it is only neces- 

 sary to determine further the ratio of the radii 



of the coils, and this may be done with great 

 accuracy by electrical means. The constant of 

 the instrument, that is, the maximum force 

 per unit current for the coils in question, has 

 been obtained in the past by interpolation be- 

 tween values of the force, calculated for vari- 

 ous assumed distances of the coils, in the 

 neighborhood of the critical value for which 

 the force is a maximum. For, although the 

 general formulas of Maxwell and Nagaoka 

 give the value of the force for any two given 

 coils, at any assumed distance with great accu- 

 racy, no formula has been heretofore pub- 

 lished for calculating at what distance the force 

 becomes a maximum. To supply this lack 

 there is derived in a paper just published by 

 the Bureau of Standards, Department of Com- 

 merce, entitled " The Calculation of the Maxi- 

 mum Force between Two Parallel, Coaxial, 

 Circular Currents," a formula which gives the 

 critical distance as a function of the ratio of 

 the radii. The latter part of the paper is de- 

 voted to the development of methods for facil- 

 itating the calculations. The formulas are 

 illustrated by numerical examples and tables, 

 and the new formulas are shown to give results 

 in agreement with those derived by more in- 

 direct and laborious method of interpolation. 

 Copies of the publication. Scientific Paper No. 

 255, may be obtained on request of the Bureau 

 of Standards, Washington, D. C. 



UNIVEBSITY AND EDUCATIONAL NEWS 



A COLONIAL mansion at 4037 Pine Street, 

 Philadelphia, modeled after Washington's 

 Mount Vernon home, has been purchased by 

 the Mask and Wig Club, the University of 

 Pennsylvania dramatic organization. After 

 extensive alterations it will be turned over to 

 the university as a gift to be used as the official 

 residence of Pennsylvania provosts. The value 

 of the gift exceeds $75,000. 



Professor Charles A. KoFom, professor of 

 zoology, University of California, is on sab- 

 batical leave for the current academic year. 

 He is spending the first half of it in research 

 work in Berkeley and wiU travel in the Orient 



