 Professor Taylor offered a gas theory of the explosion, in which he contended that deflagration would cause a pressure of gas to build up sufficiently quickly in the vaults - the entrance to which was small and through the roof—to cause the explosion.The difficulty with this explanation was in believing that the vaults were well enough sealed as to result in an explosion, when a more gradual forcing up of the cellar roof might more reasonably be anticipated.The Gateshead jury found that the explosion was caused by the interaction of sulphur and nitrate of soda, but were unable to determine a mechanism.