It was, again, as we further learn from Whitworth's little work, by the navigable Severn and Bristol that even Manchester manufacturers sent their goods to foreign countries in the days when Liverpool had still to attain pre-eminence over the south-western port. Every week, we are told, 150 packhorses went from Manchester through Stafford to Bewdley and Bridgnorth, these being in addition to two broad-wheel waggons which carried about 312 tons of cloth and Manchester wares in the year by the same route, at a cost of £3 10s. per ton. The distance, via Stafford, from Manchester to Bridgnorth is 84 miles; that from Manchester to Bewdley is 99 miles, and what the roads at this time were like we have already seen. The quantity of salt sent from Cheshire to Willington, to proceed thence along the Trent to Hull for re-shipment to London and elsewhere, is put in Josiah Wedgwood's pamphlet at "many hundred tons" a year. The navigable Trent was thus taken advantage of for the purposes of distribution; but to get to Willington from the Northwich or other salt works in Cheshire involved a road journey of about forty miles. Whitworth also gives much information as to what he calls the "amazing" development the iron industry had undergone along the Severn valley at the time he wrote (1766); and he more especially mentions that the total annual output of twenty-two furnaces and forges situate within a distance of four miles of the route of a canal he proposed should be constructed between Bristol, Liverpool, and Hull was £624,000--a figure which in those days appears to have been regarded as something prodigious. But the iron-works in question, though having the advantage of the navigable Severn in one direction, suffered from transport disadvantages in another, since their Cumberland ore (of which, says Whitworth, a very small furnace used at least 1100 tons a year) was brought down the Weaver to Winsford, in Cheshire, whence it had to be transported by road to the works on the Severn "at six {162}shillings per ton for a very small distance." On the basis of 52,780 tons only (though, we are told, "they frequently send iron to ... Chester and many other places at a great distance"), Whitworth calculates that the 32 forges in question were then paying a net sum of £32,500 a year for land transport, only, of the ore and pig-iron they received, and of the manufactured iron they sent away. "I have dwelt thus long," he says, in concluding his somewhat copious details, "upon the iron trade to show that no branch of manufacture can reap more immediate benefit from the making of these canals for navigation, or more sensibly feel the want of them when other ports of the Kingdom have them."