266 C. F. GAUSS ON A NEW INSTRUMENT FOB OBSEKVING 



sists in entirely destroying, in a very short time, vibratory motions, 

 which would otherwise be continued for several hours. The 

 damper constructed at first for the magnetometer in the magnetic 

 obsen'atory produced this effect in a very high degree, so that 

 the greatest vibratory motions disappeared entirely in a few 

 minutes. A similar arrangement can be applied to any vibrating 

 needle, to the magnetometer, and to the new apparatus here 

 treated of; and will certainly form an essential part of every ap- 

 paratus which is to be employed for telegraphing by the method 

 described above. A more complete explanation of this apparatus 

 would, however, lead us too far from our present subject. 



No particular name has been as yet given to the new appa- 

 ratus. From its chief application it might be termed an In- 

 tensitometer. But as it is applicable to as many and as ac- 

 curate magnetic measurements as the magnetometer, it has per- 

 haps an equal claim to the name. The essential difference is, 

 that the new apparatus is suspended by two threads, by which 

 a new directive force is obtained with which the magnetic force 

 is commensurable. The other differences, viz. in the mode of 

 attaching the min'or, and in the means of measuring the relative 

 amount of rotation of the several parts of the instrument, are 

 conditions necessarily arising from the objects to be obtained. 

 The new apparatus may therefore be termed a bifilar or bipensil- 

 magnetometer, to distinguish it from the older instrument, the 

 simple or unifilar magnetometer. I may express my conviction, 

 that its more extended use, and especially its employment, con- 

 jointly with the declination magnetometer, in the term observa- 

 tions, at stations Avidely remote from each other, will be soon 

 followed by an important progress in our knowledge of the 

 disturbances of the earth's magnetism. Gauss. 



[The graphical representations of the changes in the direction 

 and intensity of the horizontal force at Gottingen in the terms of 

 July 29-30, Aug. 31— Sept. 1, and Nov. 13-14, 1837, referred to 

 in the preceding memoir, page 259, are contained in the Result ate 

 aus den Beob. for 1837- As our piu'pose is rather that of illus- 

 tration than of record, it has appeared sufficient to give one of 

 these plates ; und we have selected for the purpose that of the 

 term of November 13-14, appointed expressly on those days, 

 on account of the great number of falling stars which had been 



