Watt remained at Cornwall for another month, plodding at Poldice and Wheal Virgin engines, and returned to Birmingham early in January, 1779. Though the pumping-engine had thus far proved remarkably successful, and accomplished all that Watt had promised, he was in no better spirits than before. “Though we have, in general, succeeded in our undertakings,” he wrote Dr. Black, “yet that success has, from various unavoidable circumstances, produced small profits to us; the struggles we have had with natural difficulties, and with the ignorance, prejudices, and villanies of mankind, have been very great, but I hope are now nearly come to an end, or vanquished.”[172] His difficulties were not, however, nearly at an end, as the heavy liabilities of the firm had still to be met. More money had to be borrowed; and Watt continued to groan under his intolerable burden. “The thought of the debt to Lowe, Vere, and Co.,” he wrote to his partner, “lies too heavy on my mind to leave me the proper employment of my faculties in the prosecution of our business; and, besides, common honesty will prevent me from loading the scheme with debts which might be more than it could pay.”[173] [172] Watt to Black, 12th December, 1778. [173] Watt to Boulton, 15th Jan., 1779. A more hopeful man would have borne up under these difficulties; for the reputation of the engine was increasing, and orders were coming in from various quarters. Soho was full of work; and, provided their credit could be maintained, it was clear that the undertaking on which the firm had entered could not fail to prove remunerative. Watt could not see this, but his partner did; and Boulton accordingly strained every nerve to keep up the character of the concern. While Watt was urging upon him to curtail the business, Boulton sought in all ways to extend it. He sent accounts of his marvellous engines abroad, and orders for them came in from France[174] and Holland. Watt was more alarmed than gratified by the foreign orders, fearing that the engine would be copied and extensively manufactured abroad, where patents had not yet been secured. He did not see that the best protection of all was in the superiority of his tools and mechanics, enabling first-class work to be turned out,--important advantages, in which the Soho firm had the start of the world. It is true his mechanics were liable to be bribed, and foreigners were constantly haunting Soho for the purpose of worming out the secrets of the manufacture, and decoying away the best men. Against this every precaution was taken, though sometimes in vain. Two Prussian engineers came over from Berlin in 1779, to whom Watt showed every attention; after which, in his absence, they got into the engine-room, and carefully examined all the details of “Old Bess,” making notes. When Watt returned, he was in high dudgeon, and wrote to his partner that he “could not help it unless by