Nathan Clifford

“ Persons seeking redress for the unlawful use of letters-patent in which they have an interest are obliged to allege and prove that they, or those under whom they claim, are the original and first inventors, and that the same have been infringed by the party against whom the suit is brought. Both of these allegations must be proved by the party instituting the suit; but the patent, if introduced in evidence by the complainant, affords a prima facie presumption that the supposed inventor is the original and first inventor of the patented improvement. ”

“ They, or the principal respondent, admit that he invented and devised a machine or apparatus for use as a caisson coffer-dam and diving-bell in excavating and removing rocks at certain reefs in New York harbor, that the same was constructed by and at the public expense, and has since been used solely and exclusively in the prosecution of the work to which the principal respondent has been assigned by the public authorities.
Public employment is no defence to the employ e for having converted the private property of another to the public use without his consent and without just compensation. ”

“ As evidence to show that the invention, if successful, will be of great public utility and importance, that part of the specification refers to different localities, where, from the nature of the bottom of the stream or channel, a coffer-dam could not be constructed, and where the drilling by hand from the surface would be impracticable, owing to the depth of the water and the strength of the current. ”

“ Such obstructions, where they exist in rivers or in channels affected by the ebb and flow of the tide, have the effect to contract the watercourse and to accelerate the current or flow, and consequently to increase very much the difficulties of the operator in his endeavors to blast the rocks or to remove the obstruction, except in seasons of low water, or when the tide is down. ”

“ As there employed, the term 'self anchors' means anchors capable of self-adjustment, by having at all times free play, because not attached to their sockets nor moving with the bottom section to which the sockets are attached, which sufficiently explains the difference between the word 'anchor,' as commonly used, and the term 'self anchors,' as used in the description of the patented apparatus. ”

“ Movable legs are provided for use when the bed is hard and uneven, which are attached to the lower edge of the dome, and fall by their own gravity until they bear on the bed in such a manner as to insure the horizontal position of the lower edge of the dome,-the legs being kept to their bearings by self-acting cams which hold them permanently in place. ”

“ Remarks already made show that the dam with telescopic sections was to be self-adjusting to tidal and other variations in the depth of the water where the machine is to be operated, and it is equally clear that the self anchors must be free to slide in their sockets with the rise and fall of the bottom section, in order that they may always rest on the bottom where the machine is placed for operation. ”

“ Self anchors, so called, are also provided, which are bars of iron formed and moving in sockets, as shown in the drawings, and which, by virtue of their length and free play, adapt themselves to the irregularities of the bottom, and take a rigid and steady hold during the process of drilling. ”

“ Change may be made in any direction by letting out one cable and taking up another, if it appears that the change will give the self anchors a better face for work when the dam is lowered. 6. When the drills have penetrated to the desired depth, they are withdrawn, and the diver goes down and inserts the charges. 7. The apparatus is then removed and the charges fired, when the machine is replaced as before, and the work continued. ”