Some of our readers having misunderstood some of our articles concerning the patents on Parker's Water-Wheel, which were published in our last volume, we would state that the original patent was issued Oct. 19th, 1829, and was extended seven years from its original date, it therefore expired in 1850, and is now public property. The claims of this patent are as follows :mdash; " 1st. The compound vertical percussion and re-action wheel for saw mills and other purposes, with two, four, six, or more wheels on one horizontal shaft The concentric cylinders enclosing the shaft, with the manner of supporting them. The spouts which conduct the water into the wheels, from the penstock, with their spiral terminations between the cylinders. 2nd. The improvement in the reaction wheel by making the buckets as thin at both ends as they can safely be made, and the rim no wider than sufficient to cover them. The inner concentric cylinder; the spout that directs thewatsr into the wheel; and the spiral termination of the spout between the cylinders. 3rd. Therim and blocks, or planks, that form the apertures into the wheel, and. the manner of forming the apertures. The conical covering on the Hocks, with the cylinder or box, in which the shaft runs; and the hollow or box gate, in any form, either cylindrical, square, rectangular, or irregular." Another patent was issued to Messrs. Parker for improvements in Water-wheels June, 27th, 1840, which will expire June 27th, 1854. The claim ismdash;"the placing of the said wheel or wheels, or of wheels analogous thereto, in their construction and mode of operation within air and water-tight cases or box, denominated drafts, substantially in the manner and for the purpose set forth." Our readers will now understand the exact scope of the two patents, without the necessity of relying upon the statements of others.