108 
MR. F. E. SMITH: ABSOLUTE MEASUREMENTS OF A RESISTANCE, ETC. ' 
with a precision satisfying all present demands whether purely scientific or technical. 
We believe the instrument fully realises the desires of those who were responsible for 
such measurements being made, and the results justify Lord Rayleigh’s belief that 
the ohm, as defined in absolute measure, can be realised with a precision comparable 
with that of the international ohm. The instrument can be used at any time; the 
dimensions of all its parts can be checked when desired, the probable error associated 
with a single measurement is small, and the observations do not unduly tax the 
experimenter. We have formed an estimate, based on the measurements already 
made, of the time necessary to devote to a complete re-determination supposing the 
cylinders to be stripped of the coils. The re-winding of the coils would occupy three 
days, the metrology measurements would extend over six days, and sufficient 
resistance observations could be made in eight more days. Absolute measurements of 
resistance may therefore be placed in the front rank of precision measurements. 
In conclusion, we desire to express our sincere thanks to the Drapers Company of 
London for providing a large sum of money towards the cost of the instrument, and 
to Sir Andrew Noble, F.R.S., for his generous help with the heavy metal work. 
Our most hearty thanks are hereby tendered to our Director, Dr. R. T. Glazebrook, 
C.B.,> F.R.S., who has not only given his Very valuable help and advice throughout 
the work, but has fully appreciated the many difficulties which have arisen and which 
required much time and patience to remove. 
Our best thanks are also due to Lord Rayleigh for his keen interest in the 
investigation, to Dr. Stanton for superintending the turning of the marble 
cylinders, and to many of the staff of the National Physical Laboratory, particularly 
Mr. A. Campbell and Mr. Dye, for suggestive aid throughout the investigation. 
PRESENTED 
3 APR. J9M 
