204 PROCEEDINGS OF THE [April, 1888. 



clime whose speed is to be indicated, is formed of two parts connected together 

 by an insulating sleeve, and is journaled in a frame whose upper and lower 

 parts are also connected by a threaded insulating sleeve, binding posts, connec- 

 ted with an electric bell or alarm, being secured to the lower and upper parts 

 of the frame. In grooves on opposite sides of the indicator shaft are secured 

 flat springs, with a weight, preferably of spherical form, on the outer extremi- 

 ty of each spring, a nut being fitted to move up or down on the shaft to vary 

 the length of the free ends of the spring arms. The weights are adjusted rela- 

 tive to the motion of the indicator shaft when driven by a machine, so that 

 when the machine runs at its normal speed the weights will revolve in a position 

 between the upper part of the shaft and the contact screws on either side, the 

 variation in the throw of the spring arms being indicated by the dotted Hues. 

 When the speed of the machine increases so that the weights touch the contact 

 screws, the circuit is completed and an alarm is given, a like effect being also 

 produced when the machine runs slower than its normal speed, or when it 

 stops, as the weights are then brought into contact with the upper part of the 

 indicator shaft, thus completing the circuit. The indicator may be adjusted to 

 adapt it to higher or lower speeds by turning the nut on the lower portion of 

 the indicator shaft, thus shortening or lengthening the spring arms, and also 

 by turning the contact screws in or out. 



This instrument was patented by me June 21st, 1887. 



MAY 25th, 1888. 



Tlie President in the Chair. 



JBooks deceived. 



Museum Francisco-Carolinum, Linz : 46ter Bericht. 

 Royal Society, London ; Proceedings, No. 264. 

 Norges Veextrige et Bidrag til Nord-Europas Natur- og Cultiu'- 

 historie, Christiania: 



F. C. Schtibeln, Viridarium Norvegicum, Vol. 11. 



