"I am almost in the mind of coming to pass this Winter at Berlin; that I may have the pleasure of embracing you,--perhaps as cordially as King and Kaiser here. I am, and shall always be, with all my heart,--your very good Friend, "LEFEBVRE." [Formey, _Souvenirs d'un Citoyen,_ ii. 145-148.] The Lefebvre that writes here is the same who was set to manage the last Siege of Schweidnitz, by Globes of Compression and other fine inventions; and almost went out of his wits because he could not do it. An expert ingenious creature; skilful as an engineer; had been brought into Friedrich's service by the late Balbi, during Balbi's ascendency (which ended at Olmutz long ago). At Schweidnitz, and often elsewhere, Friedrich, who had an esteem for poor Lefebvre, was good to him; and treated his excitabilities with a soft hand, not a rough. Once at Neisse (1771, second year after these Letters), on looking round at the works done since last review, in sight of all the Garrison he embraced Lefebvre, while commending his excellent performance; which filled the poor soul with a now unimaginable joy. "HELAS," says Formey, "the poor Gentleman wrote to me of his endless satisfaction; and how he hoped to get through his building, and retire on half-pay this very season, thenceforth to belong to the Academy and me; he had been Member for twenty years past." With this view, thinks Formey, he most likely hastened on his buildings too fast: certain it is, a barrack he was building tumbled suddenly, and some workmen perished in the ruins. "Enemies at Court suggested," or the accident itself suggested without any enemy, "Has not he been playing false, using cheap bad materials?"--and Friedrich ordered him arrest in his own Apartments, till the question were investigated. Excitable Lefebvre was like to lose his wits, almost to leap out of his skin. "One evening at supper, he managed to smuggle away a knife; and, in the course of the night, gave himself sixteen stabs with it; which at length sufficed. The King said, 'He has used himself worse than I should have done;' and was very sorry." Of Lefebvre's scientific structures, globes of compression and the rest, I know not whether anything is left; the above Two Notes, thrown off to Formey, were accidentally a hit, and, in the great blank, may last a long while.