Domestic Intelligence. 399 
know whether any contrivance is now in the hands of ar- 
tists for adapting the graduation of the thermometer to the 
irregularities of the bore. If there is not, the instrument of 
Mr. Kendall has the important peculiarity of supplying the 
defect,—supposing a number of points in the scale to have 
been previously ascertained by comparison with a standard 
thermometer. We are not authorised by the inventor fully 
to develope the principles of his instrument at the present 
time ; but we can state in general, that for every point in 
the scale which has been experimentally determined, the in- 
strument furnishes the ordinate of a curve. When the bore 
is uniform, the curve becomes a straight line ; but when 
variable, a continued curve is to be drawn through the ex- 
tremities of the ordinates, and to be employed instead of the 
straight line in the process of graduation. An irregular 
seale is thus furnished, which is exact at the points experi- 
mentally determined, and through the intermediate space 
varies according to the law of continuity. ‘The nature of 
the operation is such, that if a considerable number of points 
be ascertained, including those at which the ordinates are 
=~ Fie or accurately a maximum, the small errors to which 
nical process of constructing the curve is liable, 
will hava no sensible effect on the graduation. With such 
improvements in the construction of Mr. Kendall’s instru- 
ment as experience will probably suggest, we think it — 
ises to be of very essential service to the artist, incon 
ing thermometers for those experimental researches which 
require very accurate measures of temperature, and in 
which, of course, no a FE Ry ought to be placed on the 
uniformity of the bore. 
e have seen an instrument on a principle similar to that 
of Mr. Kendall, and with some valuable additions, cease 
any provision for an irregular g pos- 
session of Professor Noyes, of Hamilton College. aes is due 
o these ingenious gentlemen to state, that each has proceed- 
ed without the knowledge of the other, and that both are 
entitled to the full credit of their respective inventions. 
