Images Dated 20th March 2019

Tidal Observatory, Newlyn Harbour, Cornwall DP221138

Tidal Observatory, Newlyn Harbour, Newlyn, Cornwall. General view of tidal observatory lighthouse, shot at dawn, view from north west. Photographed by James O. Davies for Listing Review 2019. The fishing industry in Newlyn on the south coast of Cornwall expanded in the 1880s, resulting in the construction of a new harbour and two piers. In the early 20th century, the south pier was extended to give better protection to the harbour and a tidal observatory was built at its north end. The observatory was one of three constructed at the request of Ordnance Survey to establish Mean Sea Level. With the observatory being completed in 1914, hourly measurements were taken of the height of the tide between 1915 and 1921, determining that Newlyn was the most stable and therefore the principal place to establish Mean Sea Level for the entire country. Over the next 100 years, the observatory contributed key tidal data to studies in oceanography, geology and climate change. Today, all heights on Ordnance Survey maps are referenced to a brass bolt within the observatory, 4.75m above Mean Sea Level - also known as Ordnance Datum Newlyn. The Ordnance Survey gave up responsibility for the tidal observatory in 1983, but it continues to be used for scientific tidal measurements, particularly for guiding climate change and coastal management studies

Natural history, birds, sand martin (Riparia riparia)

Vintage engraving of a sand martin (Riparia riparia) or European sand martin, bank swallow in the Americas, and collared sand martin in the Indian Subcontinent, is a migratory passerine bird in the swallow family. Familiar Wild Birds, W Swaysland

© of Duncan P Walker

1137064090, Bank Swallow, Riparia Riparia

Wildflowers, Anza Borrego Desert State Park, California

© Zandria Muench Beraldo / Danita Delimont

Anza Borrego Desert State Park, Cactus, California, Colorado Desert, Danita Delimont, Desert, Discovery, Enjoyment, Flower, Landscape, Rf, Spring, Tourism, Travel, Usa, Wildflower, Zandria Muench Beraldo