This is "a study of the minute barely visible fluctuations of the articulate members of the human body." An attempt was made to control the postural orientations under which registrations were made and consideration was taken of the manner of coupling the subject to the registering system. It was concluded that "the measurements significant for individual differences in normal adults will probably be not in terms of average rates of fluctuation but in terms of either range of rate variation or of amplitude of fluctuation. The better control of pressures exerted at the end of the index finger is evidently secured by the coordination of phalangeal-metacarpal and wrist joints in such a manner as to compensate for the lesser control at the distal end of the fore-arm. Visual cues add nothing with respect to tremor to kinaesthetic control of the efferent end of the neural arc . . . In general, the greater the strain or effort in maintaining 'fixation' the less the success . . . The mechanism of tremor is less autonomous and the phenomenon more variable than has been previously supposed." (PsycINFO Database Record (c) 2006 APA, all rights reserved)