Published: 10/02/2010 11:45 - Updated: 10/02/2010 11:45

THE weather continues to mock the religion of global warming. The devotees must have very good central heating which they can afford to keep turned up and not look out of the window too often.

An interesting diary has turned up in Philadelphia. Charles Pierce kept a careful record of the weather from 1790 to 1847. In January 1790, the year after George Washington’s first inauguration, he made the following notes — “Average or median temperature of this month was 44 degrees (Fahrenheit, of course) which is the mildest month of January on record.

Fogs prevailed very much in the mornings but a hot sun soon dispersed them and the mercury often ran up to 70 in the shade. Boys were often seen swimming in the Delaware and Schuylkill rivers”.

I doubt whether there will be many boys hardy enough to go swimming in the Delaware today.

This year Philadelphia’s mean temperature in January was 32 degrees; that is 12 degrees lower than 1790.

Interestingly enough, Pierce’s record shows a very considerable cooling between 1790 and 1819, equivalent to a rate of 13 degrees Fahrenheit per century. The sunspot conditions then seem to have been very similar to those of today.

Our alarmists are getting excited about a claimed warming of around 1.2 degrees Fahrenheit in a century. They have only obtained this average by cutting out nearly three quarters of the weather stations which happened to be in the cooler places like northerly latitudes and high altitudes.

No wonder they were so keen to keep the raw data out of the hands of independently minded sceptics.

EDWARD SPALTON ETWALL