Whether it be Nero constructing his hydraulic clocks, or Prince Rupert experimenting in his laboratory, or Philip of Burgundy contriving houses full of _diableries_, such as hidden trap-doors, undermined floors, and the like, we find the same habit illustrated among rulers of every age and country. When it was suggested to Dr. Johnson that kings must be unhappy because they are deprived of the greatest of all satisfactions, easy and unreserved society, he observed that this was an ill-formed notion. “Being a king does not exclude a man from such society. Great kings have always been social. The King of Prussia, the only great king at present”--this was the Great Frederick--“is very social; Charles the Second, the last King of England who was a man of parts, was social; our Henries and Edwards were all social.” And this is specially the case with the amusements of royalty, which have oftentimes been of the most rough and arduous nature. But, as Lord Brougham once remarked, “Blessed is the man who has a hobby-horse;” and Cæsar wrote, “Under my tent, in the fiercest struggles of war, I have always found time to think of many other things”--a habit which has been recognised as a secret of strength. A hobby which was destined to have an unforeseen result was that of Peter the Great for boat-building, which manifested itself when he was sixteen years of age, and was accidental. When wandering one day about one of his country estates near the village of Ismaílovo with his companion Timmermann, he espied an old storehouse, on ransacking which with boyish curiosity his eye fell on a boat that lay in a corner, turned bottom upward. “What is that?” he inquired. “That is an English boat,” replied Timmermann; “and if you had sails in it, it would go not only with the wind, but against the wind.”