That is a perfect example of "Luxfer Prisms" coal hole, after all Luxfer was mostly responsible for pavement lights, but this example gives you 2 in 1!!!
Situated at 16 Hill Street - London the company started in October 1896 with the intention to make sunlight come into dark rooms reducing the need for artificial lighting.
"Luxfer" from the Latin words lux (light) and ferre (to carry).