Henry was baptised at Watford parish church on 13 February 1793 and was bequeathed his father William’s plumbing business in 1838. Henry married Sarah Poulton of Watford in 1843. In the 1851 census it reveals that Henry is 'plumber, painter and glazier employing 8 men' as head of the household in the High Street. He died in September 1858 at the age of 66 and was buried at Watford parish church.
Lomas worked at some of the most important houses in the area. He was interested in the national economy, and frequently recorded the collapse of the country banks at the end of 1825. His interest in the doings of Parliament led him to write about speeches, debates, the introduction of Bills, and political personalities with enthusiasm.
Of his upbringing we know nothing beyond the fact that he had been a pupil of the reverend Dr Hamilton of Hemel Hempstead. The frequent references to the Baptist church and its associates suggest sympathy with it, and his strong moral beliefs were expressed with sarcasm in October 1826 over the maladministration of local magistrates, 'those glorious unpaid'.
In 1821 the civil parish of Watford had 4,713 inhabitants The most populous area was the Town, mostly living in the alleys and courtyards leading off the High Street. The journals come to an end nine years before the first railway station was built in Watford. The River Colne was not used for navigation, and most goods and passengers were transported using horse power.
Henry Lomas seems overwhelmingly preoccupied by crime, local and national, petty and monstrous. Despite his relative affluence, he showed unexpected sympathy towards the poor who turned in their deprivation to theft. He was a great reader of newspapers, kept himself well informed about the international situation, and wrote with interest and enthusiasm about unusual weather, the parish rates, scandals, suicides and 'most horrid murders'.