138 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 2‘ 
or in words: For an ideal gas kept at constant temperature in 
a closed container with alterable volume, pressure P times 
volume V is constant. In the accuracy of ordinary scale read- 
ings, BOYLE’s law holds as a deterministic relation. Typical 
inferences from BoYLE’s law are that if the volume of the con- 
tainer is known, say V, the gas pressure is given by 
PLY, 
“IG 
- Stochastic variables subject to observational error. a)-b) Same 
variables as in Fig. 4 a-b. 
and if the pressure is known, say P,, the volume is 
(44) 
V=c/P, 
If an experiment is performed to demonstrate BoyLE’s law 
there will be small deviations owing to observational errors in 
P and V, as shown in Fig. 3b. Taking the constant c to be 
unknown it can be estimated from the data, for example by 
the method of least squares as applied to the logarithmic 
relation 
45, 
log P+log V =log c 
2| Wold - pag. 24