The Eagle Foundry was in Gloucester Road, North Laine. The site later became the Gloucester Road Drill Hall.
The Eagle Foundry's output included casting the Victoria Fountain in Old Steine.
Finding an actual official address for the site is difficult, but it seems to now be known as Gloucester Mews, and the building alongside, with a large coachway door, has a large sign saying "142 Gloucester Mews". The building that occupies the foundry's Gloucester Road frontage is by all accounts the Gloucester Road Drill Hall almost opposite Robert Street, built in about 1870, which is easy to recognise in photos (or in aerial photography) thanks to it unusual castellations along its upper front wall, probably a deliberate architectural reference to the building's original intended military purpose.
A few buildings further down the road on the same side is The Eagle pub at 125 Gloucester Road, which we're guessing is probably named after the foundry.