Sépt. 10, 1946. W. R. ‘BARRY 72,407,467 APPARATUS FOR DETERMINING GEOGRAPHIC POSITIONS CELESTIALLY vFiled Sept. 30, 1944 6 Sheets-Sheet 1 _ Sept. l0,' 1946. _ w. R. BARRY I 2,407,467 .APPARATUS ‘FOR DETERMINING ‘GEOGRAPHIC POSITIONS CELESTIALLY ‘Filed Sept. 30, 1944 6 ‘Sheets-Sheet s // Sept. 10, 1946. l w, Rf BARRY 2,407,467 . APPARATUS FOR DETERMINING GEOGRAPHIC POSITIONS CELESTIALLY Filed Sept. 30, 1944 lilél l il lglég 6‘ Sheets-Sheet 4 Sept. 10, 1946. w, R, BARRY ' ‘2,407,467 APPARATUS FOR DETERMINING GEOGRAPHIC POSITIONS CELESTIIALLY Filed'Sept. 30, 1944 > 6 Sheets-Sheet 5 sept- lo, 1946. , v w.’ R. BARRY I v2.4<‘w,467 APPARATUS. FOR *DETERMINING'GEOGRAPHIC POSITIONS CELESTIALLY ' ’ Filed Sept. 30. 1944 > a Sheets-Sheet e 120-1‘ I x \ " 122'!“ ' H i/ija" &%%a . w » 10a , ~ 10a I I‘ ‘ Patented Sept. 10, 1946 2,407,467 UNITED STATES. PATENT OFFICE APPARATUSEFOR; DETERMINING GEO‘ GRAPHIC POSITIONS‘ CELESTIALLY William’ R- Barry, Valdosta, Ga.;'Mrs. WillieR_.. Dewberry administratrix of said William R‘. Barry, deceasedv Application September 30, 1944,. Serial No; 556,622 12 Claims. ' 1 2. My invention relates to- an apparatus for the determination of geographicalpositions celestial ly, to wit, the observer’s latitude and longitude. The invention has among its objects the. produc tion of any apparatus of the kind. described en abling.v one to determine geographic positions- ce lestially in a manner which will meet the needs of aerial or other navigation. The invention has among its further objects an apparatus accurate enough for‘ aerialuse andiast enough. to be use ful in emergencies where: speed» of determination is essential and vital. It has as a particular ob ject, an apparatus-simple.- enough in‘ theory and operation so that anyone in the aircraft. could use it e?ectively and with comparatively little in struction and which would‘ incorporate a mini mum of probable errors, either careless or func tional. . (Cl. 88-23) » The number of steps involved in the obtaining of a ?x- and the complexity of the steps has a; direct bearing on two-things: ( 1) vTime necessary to obtain the ?x. (2) Number‘ of. possible errors. The ideal solution to latitude would be the shooting of ‘ the altitude of a star precisely at a celestial pole, in which case the altitude of that star would be latitude without any correction ap plied, or without the necessity of any computa tion whatsoever. By my improved apparatus in which I‘ provide a a synthetic or simulated sky system, I establish a" means of making such a direct shot, in‘ spite of the fact there is no star precisely at either North or South celestial‘ poles; My improved apparatus affords’ a rapid means of measuring local hour angle. In my improved apparatus for determin Asa simple approach. to the principles in volved and the discussion of their application in 20 ing the geographical positions celesti'ally I'employ what may be termed as a synthetic sky or- a star-. this. apparatus, I. shall. ?rst discuss‘ latitude. and ?eld or star-overlay. The synthetic sky may be the: discussion of their application in- this appa de?ned as a device presenting the appearance of ratus. The two easiest lines of. position deter the sky with a celestial pole at its center, so ar minable by means commonly in. use at present ranged that synthetic stars have the same an are the Polaris correctionshot and the-meridion 25 gular separation from other synthetic stars meas al shot andboth- are comparisons of the body and ‘ ured at a de?nite focal point that the correspond the known declination of the body, resulting, in ing real’ stars maintain. It may present‘the ap latitude. Both are special types’ of lines of po sition and can be used only under special con ditions: and pertain to latitude only. pearance of any or all of'the celestial sphere. It may‘also present a distorted image corresponding 30 to the distorted“ image of' the actual sky when Four steps are necessary, exclusive of timing, to obtain LOP’s (location of- observer’s positions) by either means, to wit: (1) Polaris correction . shot: (a) Shoot. the altitudeof. the body.v (b) Approximate LHAilocal hour angle) of Y Aries. . ' (c). Determine. correction. from the Polaris affected by optical devices employing refraction, re?ection and similar phenomena. Its charac teristic feature is that‘ it may bezmade to coin cide with the re?ection of‘the real sky as viewed from the focal point at which angular'dimensions of the synthetic sky are‘ established. Coinciding‘with. the real sky as in the preced ing paragraph, it is a means of establishing a correction table for the appropriate 40 line from the focal point'of the. synthetic sky through the center of. the synthetic sky to the ce- ~ lestial pole, and it is. further a means of establish (d) Apply the correction obtained in (c)v to ing the degree of rotation of. the actual sky about the altitude of the body determinedin the celestial pole in relation to the horizon of (a) . the earth, any plane parallel to the horizon of . I This latitude is the earth, or the plane perpendicular to the hori (2). Meridional shot: zon of‘the' earth, in which the central line so es-‘ (a) Shoot the altitude of the body. tablished lies,“ or any plane cutting celestial‘ hour (2)) Determine that. the body is near. enough circles and meridians; from the‘ sky which it may to the meridional plane. that it may be desired to establish the rotational position of be treatedv as av meridional shot. 50 the sky, using a gravitational leveling device: to (0) Determine the declination of the body establish a horizon. from tables. , > ‘ My‘ invention embodies a synthetic‘ sky, incor ((1) Apply altitude of body (a) to declina porated in or used in conjunction. with a device tionof body (c). which’ establishes a horizon or plane parallel. to This is latitude. a the plane tangent to the earth’s surface, and 2,407,467 3 Fig. 6 is a vertical section taken on the line which also establishes an observer’s meridian or 6-—6 of Fig. 3; a plane perpendicular to the plane tangent to the earth’s surface, and in which the line of sight or the line from the focal point of the synthetic Fig. 7 is a horizontal section taken on the line 1—'l of Fig. 6,, and Fig. 8 is a View of a certain sky through the center of the synthetic sky lies, C21 affords a means of directly measuring the obser ver’s latitude or the altitude of the elevated ce lestial pole above the plane tangent to the earth’s bracket and knurled knob looking in the direc tion of the arrow 8 in Fig. 1. Y . Referring to the drawings, in which an em~ bodiment of the invention is shown, it may be mentioned that the same consists generally of surface, and also the observer’s local hour angle _ of Aries (Ll-IA of Aries) or the rotational positionv 10' a housing made up of a number of parts within which is arrangeda semi transparent re?ecting of the real sky in relation to the plane perpen dicular to the plane tangent to the'e‘arth’s surface mirror constructed to permit the observation by in which lies the line from the focal point of the _ re?ection of the celestial sky as well as observa tion through the mirror of the synthetic sky. synthetic sky through the center of the'synthetic sky. ' ' There. is also provided what may be termed a latitude ring having means for establishing an ' Since any leveling device dependent upon the gravitational force may be used‘ to establish a‘ ._ . arti?cial. horizon and a longitude ring carrying what-may be termed a synthetic sky, the syn thetic sky being preferably opaque and bearing upon its face transparent indicia or symbols rep plane tangent to the earth’s surface, and simul-. taneously a line perpendicular to the plane tan gent to the earth’s surface, by employing this line resenting stars in the celestial sky. Illuminating in’ conjunction with the line in sight, a plane may be established which includes both lines. The plane so established will pass through (1) the observer’s geographical position, (2) the obser means is arranged to illuminate the synthetic sky when viewed through an eye piece along a line of sight. Suitable means is provided for varying the relation of the latitude and longi tude rings relative the housing and horizon. In Fig. 3 the parts are oriented with the re ver’s zenith, (3) the observer’s ' nadir, (4) the center of the earth, (5,) the celestial pole‘ (when synthetic sky is in coincidence with the real‘sky), ?ecting mirror exposed in the general direction toward the zenith, and showing the bubble level 30 adjusted to a level position. When the re?ect ing mirror is directed toward the celestial pole server’s hour circle is the in?nite projection of his the latitude ring and therewith the bubble level meridian. This plane so established as passing must ‘be adjusted to bring the bubble level into through the line from the observer’s zenith to his a level position. ‘ nadir and the line of sight will hereafter be des (6)'the earth’s pole, and is, therefore, the plane which cuts’ the observer’s meridian and simulta neously the observer’s hour circle, since the ob ignated as the planeof sight. N The housing consists of a boX 4 having an opening at either end along the line of sight and ' Byjestablishing a rotational scale of ‘the syn thetic sky and by using the plane of sight as an a further opening at one side 4a to permit the celestial sky to be seen through its re?ection on a suitable mirror. The box 4 is attached to an end plate of a barrel plate Ii! having an open index for the rotational scale, it may be seen that a direct reading of LHA of Aries is obtained. The measurement of the elevation of the line of sight of the synthetic sky above the horizon affords adirect reading of latitude. My improved device is designed to permit ob servation of the celestial sky simultaneously with observation of the synthetic sky and by properly setting the instrument to determine immediate ly the .latitude and, longitude of the observer up .on reference to the tables or local hour angles, thus; it requires only the few moments time for a navigator to determine his exact latitude and ; longitude. The importance of the instrument for aerial navigation is obvious. v The invention has among its other objects the production of ‘a compact, lightrweight, e?icient, inexpensive and simple device of the kind dej- r scribed which may be held in the hands or suit ably mounted on a plane or any other moving craft from which it may be desired to quickly ascertain latitude and longitude. ~ v To this end my invention consists of the novel method herein described and in the construc tion, combination and arrangement of parts here ing therethrough to correspond or register with the adjacent opening in the box 4 along the line of sight of the instrument. The barrel H] is mounted in what may be termed a barrel lati tude segment 12 which carries a latitude ring II. The barrel latitude segment and the barrel plate 10 are suitably secured together, main taining the latitude ring il in place. There is ‘a similar barrel longitude section M which car ries a longitude ring i5 which is maintained in place between the barrel segment I 4 and a lock ring l1 secured to the barrel segment [4. Seg ments l2 and M are adjustably secured together by a range adjuster [3, having a right and left thread engaging threads in the segments. Lon gitude ring 15 carries an adjustable ring I8 which carries the synthetic sky field H), which is prefer ably an opaque sheet upon which is depicted by transparent dots a representation of a celestial sky showing stars in proper angular relation to each other. At the end of the instrument and enclosing the same is a plate 21 providing a light housing. ’ I‘ in shown in the accompanying drawings. . As shown, particularly in Fig.‘3, the box 4 is Referring to the drawings: ' (35 adjustable in slide ways Illa on the barrel. and .Fig. .1 is an eye piece or near end elevation plate I0, beingr slidable so that it may be ad‘ of'my improved device; ' " ' ‘ justed in the instrument. ' The adjustment is ' Fig.- 2 is a side elevation thereof looking in the ‘brought. about by means of a screw 1 carried direction of the arrow 2 in Fig. 1; by a bracket 9 on ‘the barrel plate Ill, 8 being i Fig; 37 is a horizontal section taken on the line 3-3 of Fig. 1; V v _,Fig. 4 is a View looking in the direction'of the arrow 4 in Fig. 2; a knurled knob and set'screw locked to ‘I. On the box is an eye piece I and a suitable lens carried by an eye piece adjuster 2. The line ‘of sight through the eye piece is’ from A to B, ' .'Fig._ 5. is a vertical‘ cross section taken onthe B being the celestiali'pole of the synthetic sky ling 5'_5.Qf.'51ig;.2;, as depicted on IS. A light 20 is arranged in the : r _, 1 i. . ' . .7 2,407,467 5 line. of sight and provided with suitable. means provided‘. with. gradations- Adjustably mounted for illuminatingthe. same, such as an electric in the longitude ring. as by screwsv I821‘ is a frame light. and‘ battery which isnot shown‘ Arranged I8 which carries the synthetic sky l9 and"- per mits proper adjustment thereof-within the ring. .The light 20 is at the rear side of the. synthetic sky, as shown in Fig. 3, 22 being av re?ecting in the. box 4'. is the mirror previously described which‘ box‘ has an open. side as most clearly shown: inFigs- 2 and 3.. The re?ector or mirror is adjusted within the box at an angle. intercept ing the optical. axis or- line of sight at approxi mately forty-?ve degrees. measured along the plane of‘ elevation. As mentioned before, this surface. Assuming the device to be constructed sub stantially as shown, in using the instrument to determine latitude and longitude, for example, inthe. northern hemisphere, the synthetic sky re?ecting surface is suchthat the re?ection of ‘ the celestial sky may be seen through the; eye simulating the celestial sky as seen in the north‘; piece! and the; synthetic. sky may also be seen ern. hemisphere, the observer would face the‘ gen from l1 through the re?ecting surface. Thei?el'd eral direction of east (or west depending on'the of sight of: the instrument runs: fromfocal; point 15 location of they openiside of the box) and, hold A withan optical axis-A—l3~v and range of vision ing the instrument, bring‘ the. open side of» the ofapproximately sixteen degrees in each direc box. 4 to. face. the celestial sky, so‘ that: thesceles tion from: the optical axis Aer-B, giving a maxi ' tial sky would be re?ected by the-mirror 5 to: the mum line of sight A-C‘ and A.—-D. Correspond focal point. Looking through the sight from vA, ing angles of sight of the re?ected. image. of 20 the observer would see ‘the re?ectedv Polaris in the sky on the mirroring surface 5 is represented the mirror and at the'same time observe the oc by‘ the dotted lines E—l, intercepting the optical lestial. pole and Polaris on the synthetic sky. axisv A--B at point- E at: an angle of‘ ninety‘de When Polaris in boththe celestial‘ sky» andsyn grees, and lines F—H and G-J intercepting thetic. sky ‘coincide. the user knows that the ce A—DI and A-C',.respectively;. ' 25 The barrel segment l2 and the latitude ring ll are. operatively connectedby a. Worm. gear‘ mech anism in which the ring is provided'with teeth on the same. meshing with the teeth on a. worm lestial. poleson the celestial sky and the synthetic sky‘ coincide in the line of sight. The instru ment should be maintained sothat the level! bub ble. is in its central position, assuringthat the instrument. is level and not tilted in anyway, ISA. The latitude ring is provided with indicia 30 thereby establishing the horizon. The. observer 45 (see Fig. 2”) which. may be. observed. through then- manipulates the knob 28B; thereby adjust an. opening 35-A- inthe barrel, the indicia repre ing the relative relation- of the barrel‘i ll and lati senting degrees. or fractions. thereof. There: is tude- ring ll. Whilethe latitude ring is‘ con also provided. a knurled. knob 28A on. the worm trolled by the knob, actually the» relative move shaft. 21A for manipulating the worm and there 35 ment between the barrel and ring is brought about is also provided an adjustable; knurled knob‘ 2.833 by the tilting of-ythe- barrel‘ or housing since the which maybe secured on the; shaft through: the level is carried by the ‘ring and the ring is» main knob 28A which is provided with indiciaindicat tained in proper relation to the horizon. The ing minutes or fractions." thereof and. which co: relative movement of the barrel in angles and operates with. the pointer ‘30A. on the, bracket‘ at 40 minutes is indicated in angles in degrees» through the side ,of the. instrument. the opening 35A and on the indicated ‘angles or The latitude. ring. ll: carries a leveling. device minutes-on. the knob. At the same‘- time the ob which as: shown is a bubble. level 32: (see Fig. 3 server may turn knob 29A until the synthetic-sky as: well as. Figs. Grand. 7).. This level. provides is rotated with. the longitude, ring L5 in the bar. for the horizon withinthe instrument. In order rel l4, bringing the stars in- the synthetic sky that. the. bubble may bev read. from the eyepiece as seen through the re?ecting surface 5 to‘ co at. l', atransparent mirror 34“ is arranged within incide with. the celestial‘ stars» as re?ected on the, latitude ring. and carried thereby-with the the mirror‘5. The observer may then read‘ the leveling. device. I have‘ shown. in Fig. 3. how‘ the scales on they latitude ring H and longitude ring bubble may be illuminated. so that it may be ' 14' and knobs 28B and 29A, which gives him the‘ angles’ in degrees and minutes‘ for latitude and longitude. Of course, in making his adjust ments of the instrument, it is necessary for him readily read when the instrument is. in, use. As shown in this figure, 32.‘ represents. the level. which carries an. arm 34A to which. a mirror 3.4 is se cured, this mirror also being such» that: it. may be. usedto re?ect the bubble. as wellas to‘ permit . observation through the: same alongv the, line. of sight. A simple illuminating’ device: is shown in which, 36 designates a hollow block carrying: the bubble. level, and in. which is secured a smallélec tric lamp 40, which transmits light through, the bubble level to themirror 34. Any suitable means may be: employed for energizing the laminae for example, an electric circuit suitably connected to contacts 42 and 43 so that contact is main tained- Of course, if the source of energy is within the housing and carried by the latitude to watch the bubble so that the instrument may be maintainedv in proper relation. to. the horizon. The observer may then refer to his» tables show ing the local hour angles, and from the tables know immediately his latitude and longitude, which gives him his position geographically. Instead. of re?ecting the celestial sky the eye piece may be placed on the box opposite the side opening so that the celestial sky may be seen through it with the synthetic sky re?ected. by thesemitransparent mirror. , ‘ r The foregoing description sets forth generally the construction and operation of one embodi ment. of the invention and the methodof tak The longitude ring I5 is likewise rotated in ing readings; The apparatus is susceptible to the. housing by means of a worm 16B engaging many‘ changes and may be'greatly simpli?ed or teeth in the periphery of the ring. Knobs and 70 made more complicated, the particular instruindicating means are provided similar to that ment shown being a desirable form, however: described for the. latitude ring. This ring is also Having thus described my invention, it is ob provided with indicia 45 displayed through an . vious that various immaterial modi?cations may opening in the barrel and graduated in angles or ‘be. made in the same without departing'from'the ring. H, the connections may bedirect. , portions .th?reof, the knob 293 being similarly 75 spirit of. my invention; hence, I do. not..;wish 2,407,467 7 8 to be understood as limiting myself to the. exact position to re?ect the image of the bubble level method, form, construction, arrangement and to the eye opening, and individual means to sepa rately rotate the latitude and longitude rings. 4. In a locating device of the kind described, combination of parts herein shown and described, or uses mentioned. ' What I claim as new and, desire to secure by Letters Patent is: 1. In a locating device of the kind described, the combination of a box open at one side and having an eye'opening disposed in the longitudi nal ‘axis of the device, in one end, an extensible and contractible casing secured to said box, an combination of an ‘enclosure having an open illuminated plate in the other end of the casing in one side and an eye opening disposed in longitudinal axis of the device, in an end of 10 disposed at right angles to the longitudinal axis of the device and having indicating marks there enclosure, an illuminated plate in the other on simulating the stars observed in taking ob end of the enclosure disposed at right angles to servations, a, semi-transparent celestial sky re the longitudinal axis of the device and having ?ector in said box disposed at an angle of forty indicating marks thereon simulating the stars ?ve degrees to the line of sight from the eye open from which observations are made, a semi-trans ing to the center of the plate for re?ecting to the parent re?ector located adjacent said side open ‘eye opening the celestial sky as seen through the ing, in the enclosure and extending at an angle opening in said enclosure, a rotatable graduated of forty-?ve degrees to the line of sight from latitude ring and a rotatable graduated longitude said eye opening to the center of said illuminated plate for re?ecting to the eye opening the celes 20 ring both rotatably mounted in said casing on the longitudinal axis of the device, a bubble level tial sky as seen through the opening in said en mounted on said latitude ring, a re?ector carried closure, a circular graduated latitude indicator by said latitude ring for re?ecting the image of and a circular graduated longitude indicator both said bubble level to the eye opening, and individ rotatably mounted in said enclosure on the lon gitudinal axis thereof, level means for establish 25 ual means to independently rotate said latitude and longitude rings. ing a horizon, carried by said latitude indicator, 5. In a locating device of the kind described, and said illuminated plate being carried by said the combination of a'box open at one side and longitude indicator, and independent actuating having an eye opening disposed in the longi means for separately adjusting said latitude and tudinal axis of the device, in one end, an exten longitude indicators. sible and contractible casing secured .to said box, 2. In a locating device of the kind described, an illuminated plate in the other end of the eas the combination of a box having an open side ing disposed at right angles to the axis of the de and an eye opening disposed in the longitudinal vice and having indicating marks thereon simu axis of the device, in one end, a casing secured to said box, an opaque synthetic sky supported 35 lating the stars to be observed in taking observa tions, a semi-transparent re?ector in said box in said casing and visible through said eye open disposed at an angle of forty-?ve degrees to the ing, said synthetic sky being disposed at right line of sight from the eye opening to the center angles to the longitudinal axis of the device, a of the plate for re?ecting to the eye opening the partially transparent re?ector secured in said box at an angle of forty-?ve degrees to a line 40 celestial sky as seen through the open side of the box, a rotatable graduated latitude ring and a of sight from said eye opening to said synthetic the ing the the sky for re?ecting to the eye, opening the celes rotatable graduated longitude ring both rotatably tial sky as seen through the open side of the mounted in said casing on the longitudinal axis thereof, a bubble‘ level mounted on said latitude ring, a re?ector carried by ‘said latitude ring for re?ecting the image of said bubble level .to the eye opening, and individual means to separately box, the latter having indicating marks there on disposed in simulation of the stars from L. which observations are made, a light source behind said synthetic sky, a rotatable graduated latitude ring and a rotatable graduated longi tude ring, both rotatably mounted in said casing rotate said latitude and longitude rings, including graduated discs having graduations thereon sub on the longitudinal axis thereof with the syn- “1 dividing the graduations on the latitude and thetic sky secured to the longitude ring, a bubble level secured to said latitude ring and individual means to independently rotate the latitude and longitude ‘rings. longitude rings. ' ' 3. In a locating device of the kind described, ;_1 the combination of a box open at one side, and having an eye opening disposed in the longitudi nal axis of the device in one end, a casing secured 7 i 6. An apparatus of the kind described compris ing a housing having an eye piece at one end and a synthetic sky at the other end in the line of sight through the housing, the axes of both the eye piece and the synthetic sky being disposed in the longitudinal axis of the device, and the syn thetic sky being disposed at right angles .to said - axis, a member having a re?ecting surface dis to said box, a plate disposed at right angles to the longitudinal axis of the device supported in GO posed in the housing and cutting the line of sight between the eye piece and said synthetic sky at said casing and visible through said eye opening, van angle of forty-?ve degrees, said housing pro a partially transparent reflector secured in said vided with an opening at one side so disposed as box at an angle of forty-?ve degrees to a line of to permit observation along the sight of re?ection sight from the eye opening to the center of said plate for re?ecting to the eye opening the celes- r, 'of the celestial sky through the eye piece, said re?ecting surface constructed to re?ect the celes tial sky as seen through the opening in said en closure, the latter having indicating marks there on disposed in simulation of the stars from which observations are made, a light source behind said -plate,'a rotatable graduated latitude ring, and a rotatable graduated longitude ring both rotatably mounted in said casing disposed at right angles to the longitudinal axis thereof with the plate secured to the longitude ring, a bubble level. se cured to said latitude ring, a re?ector carried in tial sky and to permit observation through the surface of the synthetic sky, said apparatus pro vided with level means for establishing a hori~ zon, a latitude ring arranged Within the housing having indicia thereon indicating angles for de termining relative movements of the housing and latitude ring, said level means being carried by said ring, and a longitude ring also provided with ‘indicia indicating angles of rotation of the ring ‘2,407,467 i19- , within the‘ housing, said longitude ring "carrying said synthetic’ sky, and‘ individual means for ro tating said vrings independently of each other. . 7. In-anHa-pparatus of the kind described, a housing» having ‘an opening therein, ' a latitude ring arranged‘ within the housing, and rotatable upon the longitudinal axis of the-device; said housing and latitude ring being relatively ‘ad-just; able, said latitude ring provided with indicia in dicating angles, alongitude ring rotatably mount 107 a graduated rotatable latitude ring rotatably mounted'in said casing with ‘its center disposed in the longitudinal axis of the ‘housing, an illumi nated bubble level carried by said latitude ring, a graduated rotatable longitude‘ ring rotatably mounted in said casing with its center disposed in the longitudinal axis of the housing, *and's'aid illuminated plate'being mounted 'on the longitudi nal vring, and independent" means'for ‘rotating the 10 latitude ‘and longitude‘rin'gs; ” ed in the housing on the longitudinal axis of the device and provided with indicia indicating an gles of rotation, a synthetic sky carried by said 10. An apparatus of the kind described com prising in combination a housing comprising a box open at one side and at one end and having longitude ring provided with indicia thereon an eye opening at its opposite end, a casing hav simulating a view of the celestial sky, an eye 15 ing an open end secured with its open end to the piece, said synthetic sky and eye piece being dis open end of the box, an illuminated plate in the posed upon the longitudinal axis of the device other end of the casing disposed at right angles to the longitudinal axis of the housing with its thereto, a re?ector arranged within the housing center disposed in said axis, and having indicia at an angle of forty-?ve degrees to the line of 20 marks thereon simulating the stars observed in sight between the eye piece and a determined taking observations, a semi-transparent re?ector point on the synthetic Sky for re?ecting to the mounted in said box at an angle of 45 degrees to eye piece the celestial sky as seen through the the longitudinal axis of the housing, and func opening in said housing, a leveling device carried tioning to re?ect the celestial sky as it appears by said latitude ring for establishing a horizon through said side opening to said eye opening, in the apparatus, and manually operable means a graduated rotatable latitude ring rotatably for‘ controlling the relative positions of the lati mounted in said casing with its center disposed tude and longitude rings within the housing. in the longitudinal axis of the housing, an illumi 8. In an apparatus of the kind described and nated bubble level carried by said latitude ring, a in combination a housing having an eye piece iii) graduated rotatable longitude ring rotatably at one end and a plate constituting a synthetic mounted in said casing with its center disposed sky simulating the celestial sky at the other end in the longitudinal axis of the housing, and said in the line of sight through the housing, the axes illuminated plate being mounted on the longitudi of the eye piece and synthetic sky being coinci nal ring, two shafts journaled in said casing, each dent with the longitudinal axis of the device, a\ having a knob thereon, and worm pinions and member having a re?ecting surface disposed in worm gear connections between said shafts and the housing and cutting the line of sight between the latitude ring and longitude ring respectively. the eye piece ‘and said synthetic sky at an angle 11. An apparatus of the kind described com of forty-?ve degrees, said housing provided with prising in combination a housing, comprising a with the synthetic sky arranged at right angles an opening at one side so disposed as to permit observation along the sight of re?ection of the celestial sky through the eye piece, said re?ecting surface constructed to re?ect the celestial sky and permit observation through the surface of the synthetic sky, said apparatus provided with leveling means for establishing an arti?cial hori mm, a latitude ring rotatable on the longitudinal axis of the device and arranged Within the hous ing having indicia thereon indicating angles for determining relative movements of the housing and latitude ring, said leveling means being car ried by said latitude ring and a longitude ring rotatably mounted on the longitudinal axis of the device and also provided with indicia indicating angles of rotation of the ring within the housing, said longitude ring carrying said synthetic sky, means for illuminating the synthetic sky at the back face thereof, and independent means oper atively engaging said rings for rotating the same box open at one side and at one end and having an eye opening at its opposite end, a casing hav ingvan open end secured with its open end to the open end of the box, an illuminated plate in the other end of the casing disposed at right angles to the longitudinal axis of the housing with its center disposed in said axis, and having indicia marks thereon simulating the stars observed in taking observations, a semi-transparent re?ector mounted in said box at an angle of 45 degrees to the longitudinal axis of the housing, and func tioning to re?ect the celestial sky as it appears through said side opening to said eye opening, a graduated rotatable latitude ring rotatably mounted in said casing with its center disposed in the longitudinal axis of, the housing, a bubble level carried by said latitude ring, a semi-trans parent re?ector mounted on said bubble level to stand at an angle of 45 degrees to the longitudinal axis of the housing with its center disposed sub in the device. , (ii) stantially in said longitudinal axis, a graduated 9. An apparatus of the kind described compris rotatable longitude ring rotatably mounted in said ing in combination a housing comprising a box casing with its center disposed in the longitudi open at one side and at one end and having an nal axis of the housing, and said illuminated plate eye opening at its opposite end, a casing having being mounted on said longitudinal ring, means an open end secured with'its open end to the 1' for rotating said latitude ring and other means for rotating said longitude ring. open end of the box, an illuminated plate in the other end of the casing disposed at right angles 12. In a locating device of the kind described, to the longitudinal axis of the housing with its the combination of an enclosure having an open center disposed in said axis, and having indicia ing therein, an illuminated plate in the enclosure, marks thereon simulating the stars observed in disposed at right angles to an axis of the device, taking observations, a semi-transparent re?ector and having indicating marks therein simulating mounted in said box at an angle of 45 degrees the stars from which observations are made, a to the longitudinal axis of the housing, and func semi-transparent re?ector located adjacent said tioning to re?ect the celestial sky as it appears opening in the enclosure and extending at an through said side opening to said eye opening, angle of forty-?ve degrees to and intersecting 2,407,467 11 said axis, whereby light from the celestial stars as seen through said opening and the simulated stars will strike the re?ector at the same angle, an eye opening in said enclosure optically aligned 12 eratively related to said re?ector and said means for indicating the angular relation about said first mentioned axis between said re?ector and said horizon, said illuminated plate being carried by with said re?ector for simultaneously receiving, Ca said longitude indicator, and independent actu ating means for separately rotating said latitude on a common axis, both re?ected and unre?ected and longitude indicators relative to said enclosure, light striking said re?ector, a graduated latitude indicator and a graduated longitude indicator ro tatably carried by said enclosure, means for estab lishing a horizon, said latitude indicator being op- 10 about said ?rst mentioned axis. WILLIAM R. BARRY. '