608 



SCIENCE 



[N. S. Vol. XXVIII. No. 722 



is not familiar is to befog and not to illumine 

 the subject." 



The transition from mathematics which 

 "develops the quantitative reasoning power 

 and ability to think mathematically" to the 

 application of this power to concrete problems 

 is one of the hardest steps to take and — in 

 spite of the Perry movement — it is the 

 province of physics to help the student to 

 make this step. Bealizing this difficulty we 

 have introduced in the course of physics for 

 engineering students of the University of 

 Iowa " problem hours," i. e., the class is di- 

 vided into small sections spending under the 

 supervision of an instructor one afternoon a 

 week in the solution of concrete problems. 

 The results are highly satisfactory. Of 

 course there are always some " abstract " 

 thinkers who are unable to grasp the meaning 

 of the problems, and the sooner they are made 

 to see that they were not meant for engineers 

 the better. 



The only objection to the introduction of 

 the problem hours is that too little time will 

 be left for experimentation and recitations. 

 The engineering courses are so overcrowded 

 with " practical " subjects that the funda- 

 mentals, mathematics and physics, are more 

 and more crowded into the background. 

 Make the foundation broad enough to build 

 upon it the increased number of technical 

 courses. Give us more time and, if necessary, 

 lengthen the engineering course. The Uni- 

 versity of Minnesota has already done so and 

 its good example should be followed in other 

 institutions. 



The time given to physics should be one 

 and one half years. Where the entrance re- 

 quirements are sufficiently high the study of 

 mechanics in physics may well be taken up 

 in the second half of the first year, after the 

 course in trigonometry has been completed 

 and before the students have forgotten what 

 they have learned in it. The whole semester 

 should be devoted to this subject, while the 

 whole of the second year is given to the re- 

 maining part of physics, taking advantage, 

 during the latter part of the course, of the 

 training in calculus. 



Thus in closely correlating the two neces- 



sary elements, (1) the teaching of methods 

 and principles of mathematical thinking, in 

 the courses in mathematics and (2) the ap- 

 plication of these methods to concrete prob- 

 lems, in physics, the student will be properly 

 prepared to take the last step, namely, to 

 obtain technical results, in his engineering 

 courses. 



K. E. GUTHE 



Iowa Cut, Iowa 



concerning the real unicorn 

 In a certain issue of Science (February 2, 

 1906, Vol. XXIII., p. 195) Mr. C. E. Eastman 

 contributed an exceedingly interesting article 

 under " Notes on the History of Natural Sci- 

 ence," on " The Eeal Unicorn." In setting 

 forth the facts as to the origin of this 

 fabulous animal, brought to the notice of the 

 western world by Ctesias, Mr. Eastman con- 

 cludes that the source of this strange creature 

 of the medieval mind is to be traced to certain 

 relief profiles described by Ctesias as graven 

 on the walls of the Persian court at Persepolis 

 and figuring some " Asiatic ruminant new to 

 the Greeks, with the two horns appearing in 

 side-view as one." To the animal so depicted 

 Ctesias gave the name of " unicorn " or 

 " monoceros." 



Unquestionably Mr. Eastman's view as to 

 the unicorn's zoological position is probably 

 close to the real facts. It remains to de- 

 termine, if possible, what species of " Asiatic 

 ruminant " can stand sponsor for the fabulous 

 creature. Some horned beast known to the 

 ancient Persians, the horns of which would 

 appear as a single horn in profile and would 

 point forward when the animal's muzzle was 

 held downward as in the defensive attitude or 

 when grazing, could be the only one so pic- 

 tured as to give rise to the idea of a " uni- 

 corn " or " monoceros." Such a beast, I 

 think, may be seen in the male Nilghai 

 (Boselaphus tragocamelus), an Indian ante- 

 lope, ranging at present from the southern 

 foothills of the Himalaya to beyond Mysore, 

 though most abundant in the central parts 

 of Hindustan. Any one standing alongside 



