: announce- 
ment may be new that a syphon barometer contains within itself 
the elements by means of which it may be successfully compen: 
sated for te: ure. 
vompensation, outside of, and separate from the tube itself, 18 
objectionable for two vit hes. the error of temperature 
varies with ag height of the barometrical column, and also w ith 
int oj 
h the error of temperature is variable, plus or minus; 
pepe 1. System of compensation outside of the syphon, will 
necessarily Involve mechanical complexities liable to disturb- 
ance by — causes, | 
ad tons will of es involve additional items of cost, — 
which, if bestowed upon th ‘Ga | tself, 
would mane ly obviate all diffselticn. of = tube } e 
. 
i 
