Hiwacztayva Mountains. O45 
what temperature of the brass scale, (standard) the chain had heen laid off, 
as also with what weight it was precisely equal to 100 feet, I prefer abid- 
ing by the result of the comparisons with the brass scale, more especially as 
they were So numerous. 
27. PreEviousiy to commencing the measurement, the length of the rod 
1.2 was laid off seven times.’ A beam of wood with metal points, ground 
down to the 600th part of an inch was used. 43 Inches were taken and laid 
seven times by the method of dots, and arcs, making thus 301 inches. 
For greater accuracy studs of ivory had-becn let into the woud, on which 
the arcs could be drawn. The beam was compared a second time with 
the scale, after the stepping was concluded, and = the difference, if anys 
applied as a correction. The thermometer was Ase befove ‘and after the 
mean taken—the same of the comparator. When the oy which ‘cut the 
line of division on the ivory scale—did not happen iu be'in the line of steps, 
an equation was applied by dividing the square of the deviation, by twice 
the length-of the step, (eighty-six inches). ‘The following table will shew 
the result. of these seven comparisons. As determined by the division on the 
ivory scale, forming the determination of the 301 inches, and when they 
are reduced to the same state of the comparator, (the ratio of reduction 
being | to 2125) the differences do not appear great except in one case, 
“that of the 26, which may {think for this reason be rej jected, particularly as 
the great and sudden rise of temperature, (15) during the operation, induce 
an apprehension, that the brass scale might not have answered to the mean 
state, and that therefore, the reduction for temperature has been overrated. 
