SECOND REPORT OF THE DIRECTOR 1905 



4' 



main object in view; it is practically a stable mass and remains 

 nearly at rest while the earth and the supports may be undergoing 

 appreciable vibratory displacements. 



The registering apparatus consists of a cylinder driven by clock- 

 work and carrying on its surface a band of smoked paper. A 

 small lever is firmly fixed to the weight attached to the pendulum 

 and is supported by a pivot that has an independent mounting. 

 The long arm of the lever carries a stylus which is in free contact 

 with the paper and serves to trace any vibrations communicated 

 to the instrument. By shifting the pivot toward or away from 

 the pendulum, the movements (in which all parts participate 

 except the pendulum) will be correspondingly magnified or dimin- 

 ished, thus adapting the instrument for the record of shocks of 

 different intensity. The cylinder on which the record is obtained 

 makes one revolution an hour. One end of its axis is provided 

 with a steep screw thread which causes it to shift laterally as it 

 moves, so that the stylus traces a helical line on the paper. To 

 obtain a more exact time record an electric marker is provided 

 which causes a finger to pass over the cylinder at the lapse of each 

 minute. 



For complete observations a set of two instruments such as de- 

 scribed is necessary. A single instrument records but one com- 

 ponent of horizontal motion — that perpendicular to the axis of 

 the pendulum. The two are placed so that the pendulums rest 

 at right angles to each other, the one north and south and the 

 other east and west. This seismograph has been located on a 

 specially constructed foundation in the cellar of the Geological 

 Hall. 



Ill 



REPORT OF THE STATE BOTANIST 



The work of the botanical section of the State Museum for 

 the year 1905 has essentially been a continuation of the work of 

 1904. It has consisted chiefly of the investigation of our New 

 York species of Crataegus and of our fungous flora and of the 

 collection and preparation of specimens of these and other plants 

 for the State herbarium. The examination and collection of 

 specimens of the species of Crataegus found in the vicinity of 

 Albany have been carried into new localities in Essex, Warren, 

 Allegany, Livingston and Steuben counties. The result has been 



