The continuity of the observational record is sacrosanct to meteorologists. A sequence of weather observations loses much of its value if it contains gaps, since many of the statistical tricks that weather people use to analyse the data are then no longer valid.
For this reason, it has long been considered a great pity that one of the longest sequences in Ireland should have lapsed for almost two decades more than 150 years ago. And it was all because of a handsome tree that died.
The National Botanic Gardens were established during the 1790s by the Dublin Society, still a quarter of a century from being "Royal". The chosen site was three miles north of central Dublin on the southern side of the Tolka river in Glasnevin village, and in 1798 a Scotsman called John Underwood was appointed head gardener.
Since climatic conditions were of paramount importance to the work, Underwood's duties in Glasnevin included organising weather observations on the site, the first of which was carried out exactly 200 years ago today, on December 20th, 1800.
For many years Underwood was exemplary in discharging all his many tasks. He kept the Botanic Gardens in most excellent order and catalogued their contents with relentless zeal. And for the best part of two decades he was meticulous in ensuring the accuracy of the daily weather observations from Glasnevin.
Now, one of the prize exhibits at the Botanic Gardens, and said to be the biggest and the finest of its kind in Europe, was a magnificent Norfolk Island pine. When Underwood pointed out, early in 1819, that the tree had become too big for its house, the construction of a larger edifice began.
The builder was to finish the work in September, but by November the roof was still unfinished. When the temperature dropped one night to 5, the Norfolk Island pine was irrecoverably chilled; it died, and Underwood was blamed and reprimanded.
The head gardener, it seems, never recovered from this slight which he considered undeserved, but proceeded, in the words of Spencer,
To lose good days that might be better spent;
To waste long nights in pensive discontent.
With his heart no longer in the job, Underwood's performance steadily declined in the succeeding years. The Gardens became overgrown with weeds, the apprentices ran wild, and in the early 1830s the weather observations ceased entirely.
It was not until the late 1840s, long after John Underwood had gone, that one of his successors was persuaded to organise their resumption, and they have continued uninterrupted by any further controversy ever since.