Vol. 3 No. 7 



TORREYA 



July, 1903 

 A NEW AND CHEAP FORM OF AUXANOMETER 



By F. E. Lloyd 



It is very much more interesting and instructive, in elementary 

 courses in botany, to observe periodicity of growth in plants than 

 merely to demonstrate, by means of a lever, what every one knows 

 already, namely, that plants grow. It is sounder pedagogically 

 to do such experiments quantitatively, since, when so performed, 

 they mean very much more in training. It is for this reason 

 that attempts have been made to construct a cheap form of aux- 

 anometer by attaching a recording cylinder to the minute-hand 

 spindle of an ordinary clock. It is obvious, however, that the 

 centering of a cylinder, and its vertical adjustment without lateral 

 movement, are by no means easy of accomplishment. A cylinder 

 is very likely to revolve irregularly unless made with very great 

 care, a process which involves turning and centering on a lathe, 

 and skilful mechanical adjustment to the clock. I have to con- 

 fess to failure in this direction, except after a too great expendi- 

 ture of time and labor. Happily, however, this experience has 

 led me to devise a very cheap and accurate mechanism which 

 accomplishes the end desired, and this at a very small cost of 

 money, time or skill. This is done by substituting for a revolv- 

 ing cylinder, a lever, which is jogged once an hour by an arm 

 moved by the minute-spindle of a seventy -five cent clock. 



As will be seen by the illustration, the lever bearing the record 

 is fixed on a horizontal axis, and stands vertically upwards, held 

 against a block by means of a thread, reeved through a wire 

 pulley, drawn sufficiently taut by means of an attached weight. 

 This weight must be heavy enough to draw back the record 



[Vol. 3, No. 6, of Torreya, comprising pages 83-96, was issued June 12, 1903.] 



97 



