delivered the opinion of the court:
This is an appeal in an interference proceeding from the decision of the Board of Appeals of the United. States Patent Office reversing the decision of the Examiner of Interferences awarding priority of invention of the subject matter defined in the two counts in issue— Nos. 3 and 4 — to appellant Theodore W. Kenyon.
The interference is between appellant’s application, serial No. 736,566, filed .July 23, 1934, and appellee’s application, serial No. 9,689, filed March 6, 1935.
The invention defined in the counts in issue relates to a directional indicator for aircraft.
*1209The interference, as originally declared, consisted of four counts, reading as follows:
Count 1. In a flight instrument for aircraft the combination of means for indicating a turn of the craft, an air driven turbine for actuating said indicating means and means responsive to rate of turn for regulating the air drive of the turbine to actuate said indicating means whereby the latter indicates the rate of turn integrated with respect to time.
Count 2. In a flight instrument for aircraft the combination of means for indicating a turn of the craft, a turbine for operating said indicating means, air jet means for driving the turbine, and gyroscopieally controlled means responsive to rate of turn for regulating the air jet drive of the turbine.
Count 3. A directional indicator for aircraft showing the direction and amount of deviation from course, comprising a constrained gyroscope .mounted for precession through an angle proportional to the rate of turn of the craft, a fluid driven indicator and fluid actuated means controlled by the precessional position of said gyroscope for turning said indicator at a rate and direction proportional to the extent of precession of said gyroscope, whereby said indicator shows the amount of course change.
Count 4. A directional indicator for aircraft showing the direction and amount of deviation from course, comprising a constrained gyroscope mounted for precession through an angle proportional to the rate of turn of the craft, an air turbine, air flow means adapted to drive the same in either direction at variable rates, and means turned by the precession of said gyroscope governing-said flow means to drive said turbine at a rate and direction proportional to the extent of precession thereof, and an indicator actuated by said turbine.
Counts 1 and 2 originated in appellee’s application, and counts 3 and 4 in appellant’s application.
After the interference was declared, another count (No. 5) was added on motion of appellant, reading as follows:
Count 5. An aircraft flight instrument comprising a turn indicating member, an air driven turbine operatively connected to the member for actuating the member, means for pneumatically driving the turbine, • gyroscopieally controlled means responsive to rate of turn for regulating the pneumatic drive according to the right and left turn of the supporting aircraft, and means magnetically damping the turbine, whereby to actuate the turn indicator for designating degree of turn.
As to this count judgment on the record was entered against ap-pellee, from which no appeal was taken by him to the Board of Appeals.
It will be observed that counts 1 and 2 are limited to a device for “indicating a turn of the craft,” while counts 3 and 4 embrace a “directional indicator for aircraft showing the direction and amount of deviation from course.” [Italics ours.]
Appellee is the junior party, and the burden was upon him to establish priority of invention by a preponderance of the evidence.
Counsel for appellee moved to dissolve the interference as to counts 3 and 4 on the ground that appellant had no right to make the claims *1210constituting the counts in issue. The motion was denied by the Primary Examiner.
Considerable evidence was introduced by the parties, some of which was directed to the issue of the right of appellant to make the claims constituting the counts in issue. The Examiner of Interferences,, however, declining to pass upon that issue, stated in his decision that as the Primary Examiner had held that appellant’s application disclosed the subject matter defined in the counts here involved and as no “additional evidence or arguments” were “before the Examiner of Interferences other than those previously presented” he was precluded by the provisions of rule 130 of the Rules of Practice in the United States Patent Office from considering and deciding that issue'. After reviewing the evidence, the Examiner of Interferences apparently held that appellee was the first to conceive the invention but that he had failed to establish an actual reduction to practice,, and that as he had not established diligence in reducing the invention to practice at the time appellant filed his application, July 23, 1934, appellant was entitled to an award of priority of invention of the subject matter defined by the counts then in issue.
On appeal the Board of Appeals affirmed the decision of the examiner awarding to appellant priority of invention of the subject matter of counts 1 and 2, and reversed his decision with respect to counts 3 and 4, the ground of such reversal being that appellant’s application does not disclose the subject matter defined in said last named counts. From the decision of the board with respect to counts 3 and 4 appellant took the appeal before us.
The sole issue before us, as stated by counsel for each of the parties, is whether the counts are readable on appellant’s disclosure.. If they are, the decision of the Board of Appeals should be reversed. If they are not, the decision should be affirmed.
• It was the contention of counsel for appellee before the Primary Examiner and the Board of Appeals, and it is their contention here, that appellant does not disclose in his application “A directional indicator for aircraft showing the * * * amount of deviation from course,” as called for by each of the involved counts. [Italics-ours.l
It is not contended here that appellant’s application does not disclose the other structural elements defined in the counts in issue.
It is stated in appellant’s application that the instrument disclosed therein is intended to aid the pilot of an airplane in “blind flying”by indicating any turning movement of the craft from its normal course, and that for this purpose appellant discloses an illuminated screen so arranged with other structural elements that an image in the form of “checkered squares” is projected upon the screen, which image *1211is normally stationary; that is, it is stationary until a turning movement of the aircraft occurs.
The details of appellant’s device need not be set forth here. It is sufficient to say that the image is projected upon the illuminated screen by the use of an “interrupted surface located in the path of light which illuminates the screen.” The “interrupted surface” is “in the form of a peripheral toothed disk,” every fifth tooth on the disk being “foreshortened” to cause an “interruption of the image or a darkening” of the series of checkered squares on the screen. When the aircraft deviates either to the right or left of its normal course, the image is instantly animated and passes across the screen so as to “visually indicate to the pilot the occurrence of a change or deviation from the course.” Appellant states in his application that as “this movement is comparable in its rate to the rate of turn, the pilot is enabled to determine by watching the movement of the image the approximate extent to which the turning movement has changed the course of the ship and generally locate his position thereby.” [Italics not quoted.] When the ship has been turned back to its normal course, the image on the screen again becomes stationary. Appellant also states in his application that “In all cases where blind flying is required due to lack of visibility, this ability to determine the extent of any turning movement is important. This is particularly true in approaching a landing-field, where the general position of the craft with respect to the field may be located by a two-way radio. Appropriate directions from the field coupled with the indication of position afforded by the image, affords the pilot sufficient information to in all probability make a successful landing, even in those cases where there is a total lack of visibility. * * * By observing the mage and coordinating the mumber of interruptions which traverse the screen, he [the pilot] cam readily estimate the extent to which the turning movement has altered the originad direction of the craft. Obviously the number of interruptions corresponding to any given angle of turn would depend on the adjustment of the instriument and the number of toothed spaces at which interruptions occur. With the number of interruptions which correspond to any given angle [of turn] once determined,’however, the instrument functions to provide a sufficiently accurate measure of the turning movement.” [Italics ours.] It is further explained in appellant’s application that the movement of the toothed disks or image across the screen corresponds to the rate of turn and that by counting “the number of interrupted squares which pass before him” the pilot “can readily gauge the amount of the turning movement” of the aircraft.
It is apparent from appellant’s application and from the evidence of record that appellant’s instrument may be so adjusted that as each *1212of the foreshortened teeth passes across the screen and causes an interruption of the image thereon, a ten degree turn is indicated. It is also apparent from appellant’s application and from the evidence of record that it is necessary in the use of appellant’s instrument that the pilot watch the image on the screen in order that he may be informed that his craft is turning from its normal course, and that he must at least count' the number of “foreshortened” teeth passing across the screen in order that he may be informed as to the amount of deviation from his course. However, if the instrument is accurately adjusted, it is evident that by observing the image on the screen and counting the number of interrupted squares which pass across the screen, the pilot is informed as to the amount of deviation! from course as well as the direction.
That appellant’s application discloses an instrument showing the direction of deviation from course, is not questioned here.
In his decision holding that appellant’s application discloses a directional indicator for aircraft which shows the amount of deviation from course, the Primary Examiner said :
From a reading of the Kenyon specification it is obvious that the mutually normal, interrupted bars of light thrown upon the screen by the projector and interposed toothed discs constitute indications and that the number of said bars crossing the field of view during a given turn is proportional to the angular extent of said turn. On Page 13, line 18, et seq., of his application Kenyon explains that “By watching the movement of the image and counting the number of such interruptions which pass across the screen, the pilot can readily estimate the extent to which the craft has been turned from its original course at any given instant.”
As this statement is thought substantially correct, it is believed unnecessary to satisfy the terms of the counts, that Kenyon be required to show graduations on the teeth 144 or adjacent the field of view thereof. It is sufficient if the pilot can determine the turn, to a degree of accuracy, by noting the number of tooth shadows passing across the field of view. For these reasons it follows that Crane’s motion to dissolve must be and accordingly is, denied.
In its decision holding that appellant’s application did not disclose a directional indicator for aircraft showing the amount of deviation from course, the Board of Appeals said:
Claims 24 an 25 of Kenyon, corresponding to counts 3 and 4, were introduced by amendment O into the Kenyon application one day before the Crane application was filed. By amendment D it is clear that Kenyon’s position is that the image is the indicator. The image is apparently one of a series of checkered squares referred to in amendment D and in Kenyon’s brief as vertical black and white bars. Certain of these squares are interrupted at regular intervals and by watching the number of the interruptions which pass across the screen, the pilot can estimate the angle of turn.
Kenyon’s so-called indicator or image does not malee or provide a marie, record, or sign to indicate the position 0† the craft relative to a course. , The position of the craft can only be estimated, because with' Kenyon’s arrangement no zero point of reference is possible. There was something said at the hearing of *1213using element 1S6 as a reference point. Kenyon’s application on which the claims must be based makes no such contention, but even if 186 were used as a zero point, there is no zero image to go with it.
In brief, counts 3 and 4 cannot be read on the Kenyon application disclosure. Kenyon’s exhibits do not change the situation as to his right to make the counts nor does Kenyon’s argument that Crane cannot make the counts.
The question of Crane’s ■ right to-make-the counts is not'before us but we might state that Crane does show a reference line 55 for reading off degrees of the compass card. Saunier’s testimony (XQ.’s 112 and 113, pages 64 and 65, Crant’s Kecord) refers to a change in Exhibit 12 ioMoh probably would, permit an indication of the amount of deviation from course. [Italics ours.]
The board was mistaken as to the time appellant made claims corresponding to counts 3 and 4. They were made nearly one year after appellee’s application was filed, but we deem this fact to be immaterial as there is no suggestion that at the time of filing said amendment appellant had any knowledge of appellee’s application.
Appellee’s directional indicator differs materially from that of appellant. It comprises an indicating dial and, among other things, a rotatable calibrated disk, calibrated, as stated by counsel for appellee, “in terms of from 0 to I with corresponding degree indications from 0 (or 360) to 315,” hence, the naught is directly above the zero point, the numeral 1 above the 45° marking, the numeral 2 above the 90° marking, etc. When the aircraft deviates from its course, the calibrated disk rotates to the right or left, depending upon the direction of deviation with respect to the stationary zero point which serves as a “lubber’s line” for reading off the degree markings which appear on the disk. Accordingly, when appellee’s instrument is used and the plane deviates from its normal course to an extent of 45° for example, the pilot, by merely observing the instrument, is informed that his craft is off its course to the extent of 45° and it is unnecessary for him to watch the instrument constantly. However, if the aircraft deviates from its course to a degree between the degrees shown on the calibrated disk, the pilot must in part estimate the amount of deviation, although, in order to return to the normal course, it is only necessary to turn the craft until the dial shows the cipher to be. directly over the zero point or the “lubber’s line.”
However, the comparative merits of the two instruments is not the issue, before us. The question here to be determined is whether appellant’s application discloses a directional indicator for aircraft showing the amount of deviation from course.
It is suggested, although not argued, in the brief of counsel for appellant that the first clause in each of the appealed claims, which reads “A directional indicator for aircraft showing the direction and .amount of deviation- from course,” is merely an introductory clause and, is not to be regarded as a structural limitation of the invention -defined by the counts.
*1214We think it is sufficient to say that the introductory clause in each of the counts in issue is clearly an essential element of the invention defined by the counts, and is not merely introductory for the purpose of explaining the environment in which the other structural elements of the counts are designed to be used (Clarence A. Hall v. Genzo Shimadzu, 19 C. C. P. A. (Patents) 1288, 59 F. (2d) 225; In re Buttolph, 22 C. C. P. A. (Patents) 802, 73 F. (2d) 936), and that the instant case is clearly distinguishable from the decisions in the cases of Lorenz K. Braren v. George Horner, 18 C. C. P. A. (Patents) 971, 47 F. (2d) 358; In re Beplate et al., 22 C. C. P. A. (Patents) 1232,77 F. (2d) 506; Deutsch et al. v. Ball, 22 C. C. P. A. (Patents) 1322, 77 F. (2d) 930; In re Mason, Deceased, 25 C. C. P. A. (Patents) 873, 94 F. (2d) 220.
It is well settled that counts in an interference should be given the broadest construction their language will reasonably permit, but that expressly defined limitations cannot be ignored. Furthermore, in the event the language of a count or a vital term therein is susceptible of more than one construction or interpretation, as the case may be, and, therefore, ambiguous, the meaning to be given to such language or terms must be that disclosed in the application in which the counts originated.
It is our opinion that there is nothing ambiguous in the phrase of each of the counts: “A directional indicator for aircraft showing the direction and amount of deviation from course.”
The term “indicator” is defined in Webster’s New International Dictionary (2d Edition) as follows:
indicator * * * n. * * * 1. One tliat shows or points out; an indication or sign.
2. Specif., any device or apparatus, usually automatic in action, for indicating something; as a An index hand or pointer. 6 A gauge, as to show pressure, c A speed counter for an engine. <1 A registering dial, as on a dial telegraph, or in a railroad station to show the positions of trains, e Eng. in some libraries, a device indicating whether a book is out or in.
Obviously the term as used in the counts is in the sense of the definition above given under (2).
Funk &. Wagnalls New Standard Dictionary defines the term “indicator” as follows:
indicator * * * n. 1. One who or that which indicates or points out.
Specif. Any contrivance or apparatus, automatic or otherwise, which makes a mark, record, or sign to indicate the condition or position of something; as (1) a water-gage; (2) a speed-indicator for an engine; (3) dials showing the position of elevators, cages in a mine-shaft, etc.; (4) devices for recording the arrival and departure of trains, the number of fares collected in street-cars, or for testing the running of spindles for any eccentricity, etc.
*1215The terms “show” and “showing,” according to the same dictionaries, have various meanings, depending upon the context with which they are used. Upon the question before us the term “showing,” as used in the counts, must be considered in connection with the term “indicator.”
In other words, the counts call for an indicator which shows the amount of deviation from course, and among the many definitions of the terms “show” and “showing” given by Webster’s and Funk & Wagnalls dictionaries above referred to, we find one that, in our opinion, is appropriate when the term “showing” is used in connection with the term “indicator,” viz., to “give an indication by record; as, a clock shows the hour.” (Webster.)
A clock is an indicator of time. If the hour hand were to be removed from the face of a clock, we do not think it could be claimed that the clock shows the hours of the day because one could watch the minute hand, count its revolutions around the face of the clock, and, from knowing the hour when he began observation, compute the hours of the day by the number of revolutions which the minute hand had made.
Another illustration is the speedometer of an automobile. Undoubtedly in the pioneer days of speedometers the first invention was that of registering the speed per hour when placed in an automobile, with no registering of the distance traveled. Later, no doubt, came the invention of registering such distance. With a speedometer registering only the speed per hour, one by constantly observing the instrument and maintaining it at a constant speed could, by also consulting his watch at the beginning and at the end of his trip, compute the distance traveled; but could it therefore be said that a speedometer showed the distance traveled when it registered only the speed per hour? We think not, and yet it seems to us that appellant’s disclosure is of the same Character.
Surely the man who first invented a speedometer merely showing the speed per hour traveled would not be entitled to a patent including a claim for a speedometer showing not only the speed per hour but also showing the distance traveled.
If the eye of the pilot is distracted for the merest moment during ■ a turn, even by computation he could not determine the amount of the turn for he could not know how many times the illumination of the screen had been interrupted.
We are in agreement with the view of the Board of Appeals that appellant’s application does not disclose an indicator showing the “amount of deviation from course”; and to award him priority of invention of the subject matters of counts 3 and 4 would reward him for an invention which he has not disclosed.
*1216Appellant discloses no structure to support counts 3 and 4 different from that disclosed by him to support counts 1 and 2. Priority of invention of the subject matter of counts 1, 2, and 5 has: been awarded to appellant, and in our opinion these counts embrace the full measure of the invention disclosed by appellant insofar as this interference is concerned.
We are of the opinion that the Board of Appeals came to the right conclusion, and its decision is affirmed.