356 



SCIENCE 



[N. S. Vol. XLIII. No. 1106 



the side of the contact it is easy to displace 

 the pendulum one degree, making the arc of 

 vibration two degrees, which is sufficiently 

 great for testing the apparatus an hour. 



As the tuning-fork is the standard instru- 

 ment for measuring and recording short pe- 

 riods of time in physical and physiological ex- 

 periments, it is very desirable that its exact 

 rate of vibration should be ascertained under 

 the conditions to which it is subjected. It is 

 necessary to employ the graphic method to do 

 this successfully, for the friction and weight 

 of the writing point are liable to affect the 

 rate. A record of considerable length should 

 be taken to minimize the errors due to irreg- 

 ularities in the action of the electric contact. 

 In my own work the smoked paper for the 

 tracing envelops a light aluminium drum 

 which is rapidly rotated by hand. The drum 

 is mounted on a steel axis with a spiral groove 

 cut in it. A pin projecting into the groove 

 causes the drum to rotate in a spiral. As the 

 spiral movement allows long records to be 

 taken, the mean number of vibrations for a 

 considerable period can be ascertained. The 

 motion by hand is very satisfactory, as the rate 

 of rotation can be varied as required. The 

 time-marker in the circuit of the pendulum 

 should write only a few millimeters from the 

 tracing of the fork. In order to do this it is 

 necessary that the axis of the marker should 

 make an angle with that of the fork. I use a 

 clamp for this purpose which holds the object 

 in any position, and permits a delicate ad- 

 justment of the writing point. The records 

 that have been obtained with the apparatus 

 have been very regular; variations of small 

 fractions of a vibration were easily detected 

 in them. 



Frederick W. Ellis 



MoNSON, Massachusetts 



THE AMERICAN ASSOCIATION FOR 

 THE ADVANCEMENT OF SCIENCE 



SECTION M, AGRICULTURE 

 The second meeting of the Section of Agricul- 

 ture was held in Townsend Hall, Ohio State Uni- 

 versity, Columbus, December 28, 1915. The ses- 

 sions were presided over by the vice-president of 

 the section, Dean E. Davenport, of Illinois. The 



two features of the meeting were the address of 

 the retiring vice-president. Dr. L. H. Bailey, upon 

 "The Forthcoming Situation in Agricultural 

 Work," already published in Science,i and a 

 symposium on "The Eelation of Science to Meat 

 Production." The latter was participated in by 

 five speakers who presented various phases of the 

 subject. These papers brought out clearly the 

 complicated and many-sided nature of the prob- 

 lem of meat production and the part which seienje 

 is playing in promoting, safeguarding and ration- 

 alizing the industry. 



The symposium was led by President W. 0. 

 Thompson, of Ohio iState University, who defined 

 ' ' The Nature of the Problem. ' ' The background 

 of it lies in the fact that the people of this coun- 

 try have been a meat-eating people for many gen- 

 erations, and any limit to the supply or any exces- 

 sive cost calls forth widespread protest. The prob- 

 lem of meat production was defined to be largely 

 an economic one in farm management. It has 

 been affected by the numerous changes in agricul- 

 tural conditions over the country, the extension of 

 farming in the west, the increase in the tenant 

 system, and the development of the dairy indus- 

 try, even in the vicinity of small towns, all of 

 which have affected the raising and fattening of 

 beef cattle. 



The large risk sustained in live-stock keeping 

 has contributed another angle, as has also the 

 problem of advantageous marketing. The prob- 

 lem of maintaining the requisite meat supply is 

 not a haphazard one, but includes very definite 

 phases, such as its relations to systems of farming 

 and to the maintenance of soil fertility, the 

 maintenance of health of live stock to reduce the 

 risk, provision of adequate marketing facilities 

 and conditions, and the intelligent feeding and 

 handling of meat animals. The point was empha- 

 sized that the taste for meat has been struggling 

 for existence at the expense of the farmer, and 

 that consideration of the problem of continued 

 supply must be based on broad considerations, in 

 the firm belief that the laborer shall receive his 

 reward. 



President H. J. Waters, of the Kansas Agricul- 

 tural College, enumerated some of the ways in 

 which science may help live-stock farming, as by 

 showing the farmer how a surplus of feed may be 

 carried over, in the silo for example, to equalize 

 the feed supply from year to year; by the proper 

 balancing of feeds, a knowledge of the values of 



1 1916, Science, N. S., Vol. XLIII., p. 77. 



