477 



and power-station are of no consequence, the only resnlt will be, 

 that the cam IJ is a little more to the right or to the left at the 

 moment, at which the second circuit is closed, so that only the ratio 

 of the rapidl}^ and slowly revolving parts of the axis of the fly-wheel 

 may be altered every second. This is of no importance, because the 

 axis of the clinostat revolves at a much slower rate and the movement 

 is transmitted to this by means of the cog-wheels 4, etc. 



To the horizontal axis of the clinostat a conical cog-weel has 

 been fixed, in which another conical cog-wheel catches, fastened to 

 an adjustable axis 5. This latter axi/ has been fitted on in such a 

 way, that it can revolve on the horizontal axis and can be fixed, 

 while the rotatory movement is not impeded. This enables us to 

 give the axis of the clinostat any desirable position. By fixing the 

 adjustable axis and releasing the adjusting-apparatus, a rotation of the 

 plant perpendicular lo the horizontal axis may be obtained. This 

 arrangement is shown in fig. 2; the adjustable axis is fastejied with 

 the screw A, the adjusting-apparatus with the handle B. 



Fig. 3 gives a backview of the whole apparatus, in which the 

 arrangement of fig. 2 has not yet been fitted on. This figure shows, 

 that the apparatus is comparatively small and may easily be removed 

 by one person. The position of the axis too may be modified 

 without any difficulty during the experiment. 



To the simple construction it is owing that the costs of purchase 

 are considerably lower than of any other satisfactory clinostat. An 

 objection is, that the motor keeps running throughout the experiment 

 and therefore constantly uses current. But then the axis revolves 

 with great power, so that considerable weights can be carried, while 

 excentric loading that is rather considerable, does not cause any 

 alteration in the regular running of the clinostat. 



In order to check the running of this clinostat and compare it 

 with Pfeffer's and van Harreveld's clinostats, the recording- 

 apparatus of the auxanometer of Koningsberger ^) was used. 



For this purpose electrodes were fixed to the axis of the 

 clinostat either right opposite to each other or at an angle of 90°, 

 in such a way, that after each full rotation of the axis, the top of 

 such an electrode once made contact in a mercurydish and in this 

 way a circuit was closed for a short moment. Closing that circuit 

 caused a writing glass-pen to be stopped in its course and to be 



^) V. J. Koningsberger, A method of recording growth under various external 

 influences. Proceedings Kon. Ak. v. Wet. Amsterdam. W. en Nat. Afd. XXX, 

 6/7. 1921. 



