As to parks and public promenades, New-York is lamentably deficient--the whole space thus appropriated being hardly more than eighty acres, for the refreshment of a population which will soon cease to be counted by hundreds of thousands. "Eight million dollars worth of land," say the city fathers, "is as much as we can afford!" The penurious estimate which has resulted in this miserable deficiency has been long and ably combated by patriotic and clear-headed citizens, but their influence has as yet proved wholly unavailing. Public meetings have been now and then held, with a view of exciting a general interest in this important matter, but they invariably end in fruitless resolutions. The island still affords good sites for public gardens, but there is scarce a gleam of hope that any of them will be reserved. The few breathing spaces that now exist, are thronged, and by the very people who most need them--children and laboring people. The vicinity of the fountains is full of loiterers, quietly watching the play of the bright water, and growing, we may hope, milder and better by the gentle influence. At certain hours of the day whole troops of merry children, with their attendants, make the walks alive and resounding. The hoop, the ball, the velocipede, the skipping-rope, rejoice the grass and sunshine, and the eyes of the thoughtful spectator, who sees health in every bounding motion, and hears joy in every tiny shout. It is strange that the citizens do not, one and all, cry aloud for the easy and happy open-air extension of their too often crowded homes. London is the world's example in this thing. A park suited to riding and driving is especially needed because of the wretched pavement which still disgraces the greater portion of New-York. The first thing that strikes an American returning from Europe is the inferiority of the pavements of the Atlantic cities; and New-York, in particular, is, in this respect, hardly a whit before the far-famed corduroy roads of the wild West. In 1846 a great improvement was begun, called, after the inventor, the Russ pavement, and thus far seeming to meet all the difficulties of the case, including the severe frosts and sudden changes of the climate. The plan is, however, so expensive that it will probably be long before it is fully adopted. It requires square blocks of stone, about ten inches in depth, laid diagonally with the wheel-track, and resting on a substructure of concrete, which again rests upon a foundation of granite chips, the whole forming a consolidated mass, eighteen inches thick, so arranged as to be lifted in sections to afford access to the gas and water pipes. This has been largely tried in Broadway, and has stood the test for six years.