 These records are for the years 1752 to 1755, while records dating from 1764 to 1768 for another boat called "Success" indicate that downriver traffic was mainly coal, with some cinders, paving stones and slates, while upriver traffic was exclusively limestone.Holt Leigh's diaries indicate that tolls for 1772 were £414, which would suggest that over 10,000 tons of goods were carried that year.Total costs for construction of the navigation were some £12,385, which had risen to £32,226 by 1768, by the time interest and maintenance charges were included.