48 THE POPULAR SCIENCE MONTHLY. 



of the everlasting, are to stand for it ; and the highest compliment 

 man ever receives from Heaven is the sending to him its disguised 

 and discredited angels." This is a grand exhortation, and has, no 

 doubt, thrilled many a reader with enthusiasm for the rising thoughts 

 of his time. But the difficulty still remains, how to identify the celestial 

 messengers ! Such are the eccentricities of human judgment, that the 

 sympathy which Mr. Emerson invokes is as likely to be given to the 

 worthless as to the worthy. And what shall we say about the duty 

 of common mortals respecting the " disguised and discredited angels," 

 when the Seer himself snubs the author of " First Principles " as a 

 " stock-writer," and says to the author of that unclean imposture 

 "Leaves of Grass" "I greet you at the beginning of a great career ? " 



HUMAN LOCOMOTION. 



THE movements executed by animals in transporting themselves 

 from place to place have long engaged the attention of observers ; 

 and, as animals which travel on the land are more easily got at than 

 those which frequent the sea and the air, it is the motions of such that 

 we know most about. Yet much remains to be learned of the modes 

 of progression of even the most familiar of these ; and not a little prob- 

 ably will have to be unlearned that recent investigations have shown 

 to be erroneous. 



At first sight, the operations of walking and running, as displayed 

 by both two-legged and four-legged creatures, may appear simple 

 enough, but all attempts to analyze and explain them have shown that 

 in reality they are very complex, so that there has arisen a wide di- 

 versity of opinion concerning their real nature. These disagreements 

 among the investigators of the subject can only be accounted for on 

 the principle of the insufficiency of the means at their command for 

 complete investigation ; and the confusion has been further increased 

 by the difficulty of expressing in words the rhythm, duration, and 

 phases of the rapid and complex movements involved. 



Prof. E. J. Marey, of the College of France, a skillful physiologist, 

 and the inventor of the various delicate mechanical appliances for 

 tracing and registering obscure animal motions, has contributed to the 

 " International Scientific Series " a work entitled " Animal Mechanism," 

 in which the subject of terrestrial locomotion, as typified in man and 

 in the horse, is fully treated. Prof. Marey has devised an apparatus 

 which, applied to the extremities of a moving animal, enables each 

 limb to write out a description, or make a picture of its own actions, 

 so that the duration and phases of its movements, its periods of rest, 

 and the relations of these to the corresponding features in the motions 



