Juhn Middleton, of Newark, N. J.,has invented it new mode of constructing rocking chairs, which makes them more portable than heretofore, and at the same time equally easy and convenient for use. They may be folded up so as to occupy but a very small compass when it is required to carry them from one locality to another, or when they are not desired tor use. The improvement is in the manner of connecting the severel parts of the irame together, so as to be easily, folded. The rockers are connected by joints and pivots, so that one end of the rockers may be detached from the legs when not in use. Measures have been taken to secure a patent. The natural salt ponds on the Florida Keys, which, in 1848, yielded about 75,000 bushels of salt, have been, during the last winter greatly improved and extended, so that the evaporating surface is now 600 acres, and will soon be increased to 800. During the winter the ponds have contained pickle sufficient to make 500 bushels of salt.