The 1851 census of Places of Public Religious Worship tells us of Salem Chapel which was in Minster Street. The Salem return says that Salem seated 420 and was full on Sunday evenings. On the Sunday of the census, there were 590 packed in because of a funeral sermon. In the mornings attendance averaged 250 with a further 70 children.
The return was completed by Edward Bishop, the minister, of 34 Welldale Street.
Salem was replaced by the impressive chapel in London Street purchased in 1866 which seated 850 people. You can see it here.