(after stating the facts as above). In this case we do not think it necessary to take up the question of validity at all, since we are satisfied that the claim should not receive a broad interpretation, because it is for only one feature of a highly complicated and detailed machine coming into a closely settled art, and the invention must be therefore confined to the disclosure. The issue of infringement turns on the interpretation of the words, “for continuously feeding the paper without feeding the type wheel.” We pass the validity of the disclaimer, assuming for argument’s sake, that the phrase, “constantly acting source of power,” is to be read, “a constantly rotating drive shaft.” The words in question ought to be interpreted by the specifications as far as these throw any light, and they not only throw light, but absolutely define and control these words as used in the claim. On page 3, lines 81-100, the patentee speaks of a mechanism for shifting the operating clutch, which is lettered C on the drawings, and to understand which perhaps the best figure for practical purposes is Figure 2, although the section drawing in Figure 9 also illustrates it. He then says that, before describing the present mechanism for shifting this operating clutch and its operation, he “will state generally that according to my invention means are provided for continuously feeding the paper without feeding the type wheel, and to be more particular the means for accomplishing this end are connected with the mechanism for shifting the operating clutch C.” This mechanism is clearly that referred to in claim 12. The description of the operation of the line-spacing mechanism begins at page 5, line 130, and ends at page 6, line 88. It describes how the lever, 113, rocks idly , so long as the pins, 121 and 120, are not in abutment. It is during this period that the carriage of the type wheel is being advanced to the right with every oscillation of the escapement lever, 93, actuated by the magnet, 99, through its proper key, a device clearly-shown in Figure 1. The description of how the type wheel is retracted and a single line of paper is fed begins on page 6, line 18, and ends on the same page at line 74. The important part of this specification for our present purposes is lines 74-88 on page 6, which are as follows:

“It will now be seen that after the operating clutch 0 has been shifted in such manner that the type wheel mover shaft 8 retracts the type wheel 7 against the buffer 72 by continuing to successively actuate the armature 97, causing the rotation of the escapement) wheel 70 tooth by tooth, the paper may be fed line by line without feeding the type wheel, 7; forward, for with (he type wheel mover resting against buffer 72, as long as the stop 126 on shaft 6 is maintained in such position that finger 121 will hit against it whenever the lever US is actuated, rotation of the type wheel mover shaft in either direction cannot take place.”

*124It is quite clear from this description what the patentee meant. By a continual feed of paper he meant that the operator should be able to make successive blank lines without moving the type wheel in any degree whatever, and it is also clear that he supposed he had solved this. He presupposed that the pins, 121, 126, should remain in abutment by pressing the proper key operating the type-wheel shaft, 6. While they so remain, any energizing of the poles, 99, allows one tooth of the escape wheel, 70, to be released, this causes the cam, 65, to rock the lever, 113, upon the pin, 126, as a fulcrum and necessarily to move the lever, 110, which acts as an escapement for the paper mechanism. Now the member, 60, of the clutch, slips freely on the shaft (page 2, lines 74, 75), and the gears, 61¡,, 66, therefore rotate the worm shaft, <?, only by virtue of the clutch, 57. Indeed, the only member of the clutch C rigidly attached to the shaft, 8, is the bracket, 58, which is adjustably connected with the shaft by a set screw, 59, Figure'9. If the clutch 57 were a friction clutch, then when the pin, 105, began to push away the member, 57, of the clutch, as it would do at once upon the beginning of the action of the cam, 65, it would at once release that clutch and make the member, 60, turn idly upon the shaft, 8. Such a clutch would therefore certainly enable the line-spacing mechanism to operate without the most minute angle of rotation of the shaft, 8. In the design in question, while it may be debatable whether the operation of the pin, 105, to disengage the clutch, 57, 60, will be quick enough to avoid a minute angle of revolution of the shaft, 8, which would carry the type wheel carriage a minute distance away from the buffei', 72, to be returned as soon as the clutch, 52, 56, engaged and retracted it, it is clear that the patentee thought it would, because the language quoted is explicit and clearly indicates that the clutch, 57, 60, will disengage too quickly to move the type wheel carriage at all. No other meaning can be attributed to the phrase, “rotation of the type wheel mover shaft in either direction cannot take place,” page 7, lines 86-88. As this is the operation referred to by the words in claim 12, “for continually feeding the paper without feeding the type wheel,” it is irrelevant whether in practice the type wheel carriage is in fact moved a step or two.to the right to avoid “skating through.” This was the patent, and if the pateñtee has now learned that for “unison” he must abandon rigid adherence to this feature, he can surely make no monopoly out of his inability to foretell the exact results of his invention and out of his subsequent practice.

Turning now to the defendant’s device, we find quite a different organization. As long as the point, 32, remains in contact at the point, 33, the circuit is made and energizes the magnet, 26, which will hold down the armature, and allow only one tooth of the escapement to feed the paper. Another space cannot be made without moving the type carriage to the right far enough to break the circuit, at 32, 33, de-energize the magnet, and release the armature. It is functionally necessary, therefore, to oscillate the type carriage in order to give a continuous line spacing, and that is directly the contrary of the claim in suit. This was not true in the so-called “contempt” machine, because, when the pins, 121, 126[ were in abutment, any operation of *125the cam, 65, would continue to make successive contacts at the point, WOa, after the type wheel carriage had been retracted to its step by the first raising of the bar, No oscillation of the wheel carriage was necessary for continuous line spacing. The operation of the defendant’s two machines in this respect was therefore diametrically opposed. e

The defendant derives directly from Merritt & Joy and Essick and has borrowed nothing from the patent in suit so far as concerns claim 12. In both these patents it is absolutely necessary for the type wheel carriage to move to the right for a continuous line spacing; either by the momentum of the type wheel carriage, or by its closing of a circuit to operate the paper feed, the return, and only the return, can feed the paper. It is true that in Merritt & Joy the momentum of the type wheel carriage furnishes the sole energy for this purpose, a momentum imparted to it by the retracting spring in which some of the energy of the constantly driven shaft has been stored. It was probably in order to differentiate the patent in suit from his patent, that the patentee provided that the type wheel -carriage should not move to the right. But in Essick the paper feed not only required a movement of the type wheel carriage, but also was actuated by a completely independent source of energy, a battery, and the only energy used from the source which supplied the type wheel carriage was to close the contact. It is an abuse of words to speak of the closing of those contacts as though it drove the paper feed. However, we may pass by that, because the defendant’s machine, and so Essick’s, which he has borrowed, can operate only by a movement of the type wheel carriage, quite as much as Merritt & Joy, and that for present purposes is a crucial distinction. This movement is not a mere accidental concomitant, associated for other reasons, as is the movement of the type wheel carriage in actual practice in the patent in suit; it is a functional necessity, the condition of any operation whatever of the paper feed, the direct opposite of the theory upon which that patent was planned. It makes no difference whether the designer, of the defendant’s machine was deliberately trying to circumvent the patent; whatever his purpose, he had open to him the materials of the art, and' so long as he took no suggestion from the patent in suit he did not invade its monopoly.

The decree is reversed, and the complaint dismissed, with costs in both courts.