NOVEMBEB 11, 1910] 



SCIENCE 



663 



which is to continue until January, 1911, and 

 to be followed by a " seminary " course in 

 1911-12. Professor Boas begins in November, 

 1910, Professor Eichet in January, 1911, etc. 

 The qualifications for enrolment are gradua- 

 tion from a university school (college) and 

 high honors in subjects related to that to be 

 pursued. The first course given under these 

 restrictions had an enrolment of fifty-five. It 

 is expected that these professors will devote 

 their courses to research as well as to instruc- 

 tion. 



At the University of Pennsylvania, Dr. 

 Arthur Holmes and Dr. F. M. Urban have 

 been advanced to assistant professorships and 

 Mr. S. F. Fernberger to an instructorship in 

 psychology. 



At Western Reserve University, Mr. Wil- 

 liam L. Dolley has been appointed instructor 

 in biology, and Mr. Edward H. Sensel in- 

 structor in chemistry. 



Mr. a. E. Shipley, F.R.S., fellow and tutor 

 of Christ's College, Cambridge University, has 

 been elected master of the college in succes- 

 sion to the late Dr. John Peile. 



The dedication exercises for the new build- 

 ing for entomology, zoology and geology at the 

 Massachusetts Agricultural College will be 

 held Friday, November 11. Dr. L. O. Howard, 

 of Washington, will give the dedicatory ad- 

 dress. The building is 100 by 120 feet, of 

 colonial style and of the letter H design. It 

 is made of brick, steel and concrete, thus 

 giving a fire-resisting structure. It was built 

 and equipped at a cost of about $95,000. In 

 the basement are spacious laboratories for 

 geology and mineralogy and a rock museum; 

 also a laboratory for insecticide analysis and 

 two rooms for spraying apparatus. On the 

 first floor are two large laboratories for zoology 

 and the main floor of the zoological museum; 

 also two rooms and an office for the experi- 

 mental work in entomology with a greenhouse 

 attached and three offices for the department 

 of zoology and geology. On the third floor 

 are two large laboratories for entomology, an 

 insect collection room, a small lecture room and 

 the library; also a laboratory for advanced 

 zoology, the gallery of the zoological museum 



and two offices for the department of entomol- 

 ogy. In the main part of the building there 

 is also a large amphitheater lecture hall. Pro- 

 fessor H. T. Femald is at the head of the 

 department of entomology and Professor C. E. 

 Gordon at the head of the department of zool- 

 ogy and geology. 



DISGV88I0N AND CORRESPONDENCE 



THE LOCUS OF A MOVING POINT WHEN THE QUO- 

 TIENT or ITS DISTANCES FROM TWO FIXED 

 POINTS IS CONSTANT 



Eeferring to the digest of a paper by Mr. 

 John F. Lanneau under the above-mentioned 

 title, in Science, No. 806, it may be of interest 

 to state that the locus is of importance in the 

 theory of electric cables and transmission 

 lines. The circles represent the directions of 

 magnetic lines of force, created by a current 

 through a loop consisting of two parallel wires. 

 The orthogonal system of circles corresponds 

 to electrostatic stresses between the wires. Or 

 else, the first system determines equipotential 

 electrostatic surfaces, while the second system 

 gives surfaces of equal electromagnetic poten- 

 tial. 



When telephone wires run parallel to a 

 power transmission line it is of importance to 

 place each telephone loop in such a position 

 with respect to the power line, as to have a 

 minimum of inductive disturbance, that is to 

 say, a minimum of roaring in the telephone. 

 For this purpose it is convenient to draw the 

 circles in question, representing magnetic 

 lines of force around the power transmission 

 line. The two wires of the telephone line 

 must lie on the same circle. In the case of a 

 three-phase line the same is split, for the pur- 

 poses of computation, into two single-phase 

 lines, and circles are drawn for each loop 

 separately. The telephone wires are located 

 so as to lie approximately on some one circle 

 belonging to each single-phase loop. 



The two fixed points in Mr. Lanneau's prob- 

 lem are inverse points with respect to the sys- 

 tem of circles; this is according to a weU- 

 known theorem in elementary geometry. They 

 do not coincide with the centers of the wires 

 in the electrical problem. The cross-sections 



