Jonathan Otley

Jonathan Otley (19 January 1766 — 7 December 1856) was a self-taught English geologist whose detailed observations in the English Lake District set the foundations for the study of that area's geology.

Early life Otley was born on 19 January 1766 at Nook House (also known as The Scroggs) close to Loughrigg Tarn, Cumbria. He came from a working family earning his living making wooden sieves and baskets with his father,

In 1797 Otley moved into a cottage near the centre of Keswick, in King's Head Court, where he spent the rest of his life. The cottage, which still exists, was up a flight of steps and became known as "Jonathan's Up the Steps".

Over the following 25 years Dalton visited the Lake District nearly every summer. He met Otley on at least 19 of those visits and Otley would generally accompany him on his excursions. and when Dalton was taking barometric readings in the lakeland hills, Otley would check his own altitude measurements against Dalton's barometric measurements. Otley became both an assistant and a friend to Dalton, acting in the capacity of both a colleague and a paid guide.

Otley had been preparing a topographic map of the Lake District which was published in 1818. The map was also engraved by him and an updated copy was included in the guide to the lakes that he first published in 1823. The 1823 guide included his geological insights, Sedgwick described it as "the best guide to the Lakes that ever was written". and in 1820 he published the first scientific account of the geology of the Lake District. He grouped the strata of the Lake District into three principal units which are now know to be of Lower Palaeozoic age. Those three broad divisions are still in use in the 21st century (although the names of the units have been changed and sub-units have be established). He named the three divisions as "clay-slates", "green slates and porphyries" and "greywacke", those correspond with what is now known as the Skiddaw Group, the Eycott and Borrowdale volcanic groups, and the Windermere Supergroup.

The following year, when William Smith (who made the first geological map of Britain) was carrying out a traverse of the Lake District, he and Otley met and compared notes on the region's geology. during which Sedgwick's work first "built on the foundations of geological knowledge laid by Otley", and later "massively extending" Otley's contribution. and J.E. Marr (who was the Woodwardian Professor from 1917-1930), wrote that Otley "must undoubtedly be regarded as the Father of Lakeland Geology".

In 1827 Otley produced one of the first geological maps of the Lake District.

Later life and legacy

Otley died in Keswick on 7 December 1856 and was buried in Crosthwaite Churchyard. A simple slate plaque acts as a memorial on the flight of stone steps, Jonathan's Steps, in King’s Head Court, close by Keswick's Moot Hall.

He recorded the summer level of Derwent Water during particularly dry years by cutting a notch-mark in the rocks below Friars’ Crag, the marks record the lake's level in 1824, 1826, 1844 and 1852 and they can still be seen in dry seasons.