Why does the writer consider even barometers as also "useless" and "misleading"? Justify his remarks by refering to one hanging at a hotel in Oxford.

Basically the one hanging at a hotel on Oxford never got the weather right. Despite the author adjusting it and reading it over many days, he received a very inaccurate forecast. Sometimes is read "very dry" and at others it read "much heat". All the while the rain poured down outside.