US1763827A - Observation instrument - Google Patents

Description

Jime1 7, 1930. HTEPH N 1,763,827

OBSERVATION INSTRUMENT Filed June 14, 1928 2 Sheets-Sheet l I 5 J WP F/GZ V 25 4 25 v M/Vf/W'fi/F I JJZEP/ILW June 1.7, 1930. J. STEPHEN 1,763,827

OBSERVATION INSTRUMENT 7 Filed June-l4, 1928 2 Sheets-Sheet 2 //VVI NTOR.

J. STEPHEN Patented June 1'7, 1930 UNITED STATES PATENT OFFICE JAMES STEPHEN, OEE TORONTO, ONTARIO, CANADA, ASSIGNOR OF SIXTY PER GENT TO CAROLYNE HARWOOD QUIPP, F TORONTO, CANADA OBSERVATION INSTRUMENT Application filed June 14,

My invention relates to improvements in observation instruments, and the object of the invention is to devise a device whereby any local time may be found and by which the latitude and longitude of the locality at which the observation is taken may be derived from calculations based on the standard time and the found local time, and it consists essentially of the arrangement and construe tion of parts as hereinafter more particularly explained.

Fig. 1 is a perspective view of my device looking from the operative side of the instrument or from the side on which the observation is taken.

Fig. 2 is a similar view to Fig. 1 looking at the reverse side.

Fig. 3 is a cross sectional view through the instrument taken from back to front.

In the drawings like characters of refer ence indicate corresponding parts in each figure.

1 indicates a bowl adapted to contain mercury, spirits or other suitable fluid upon wh ch 2 a disc 2 floats upon which the observation instrument is carried so that it will automatlcallv level itself in any position in which it is placed. 3 and 4 are standard frames suitably secured to the disc 2 and extending upward therefrom in a spaced position and provided with inwardly extending opposing pointed pintles 5 and 6. 7 is a cylinder provided with bearing recesses 7*, at diametrically opposite points in whlch the pointed ends of the pintles 5 and 6 engage so as to swingably support the cylinder so that its axis may be readily adjusted to any angular position. 8 and 9 are annular members surrounding the cylinder 7 adjacent its front and rear end and held in place by flanges 10 and 11 so that such annular members may be turned to any desired position.

The annular member 8 is provided with an operating handle 8 by which the annular member 8 is turned circumt'erentially to any desired position.

12 is a tube which is supported centrally within the cylinder 7 at a slight angle to its axis as will hereinafter be explained. The

tube is supported by arms 13 connecting the 1928. Serial No. 285,383.

same to the annular member 8 and by arms 1-4 connecting the tube to the annular member 9.

It will thus be seen that when the handle 8* is operated the annular member 8, tube 12, arms 13 and 1 1 and ring 9 will turn as one unit.

At the inner side of annular member 8 is turnably supported an annular time disc 15 turnable around the cylinder 7.

16 is a calendar disc which is similar to the disc 15and turnably supported upon the cylinder 7 and held against the disc 15 and in place from longitudinal movement by a flange Each half of the time disc 15 is divided into 12 hours as will be clearly seen upon referring to Fig. 2, each of the hour spaces being divided into 5 minute spaces.

It may be pointed out that there are 365 days in the year. 7

The disc 16 is divided into 73 spaces each space approximating a 5 day space and these spaces are divided into series in proportion to the number of days in each month of the year such as in January 31 days, February 28 days, March 31 days, etc.

17 is a stationary pointer carried by the cylinder 7 and coacting with the calendar disc 16.. The calendar disc 16 is provided with a lug extending radially therefrom as indicated at 18. 19 is a lug extending from the time disc 15 and provided with a circumferential slot 20.

21 is a set screw extending through the slot 20 into the lug 18 so that the lugs 18 and I 19 may be locked together and the time disc 15 and calendar disc 16 in the position desired as will hereinafter appear.

22 is a radial slot which may be formed in an enlargement of one of the arms 13 or in a separate arm attached to the annular meniber 8. This portion is also provided with a pointer 23 which coacts with the time disc 15. 24 is a supplemental longitudinally slotted member attached to the annular member' 8 on the lower portion thereof for a purpose which will hereinafter appear.

25 is a pointer carried by the cylinder 7 and extending radially therefrom and coacting with the stationary graduated scale 26 carried by the floating disc 2, the scale 26 being divided from naught to ninety.

Having described the principal parts involved in my invention I will briefly describe the operation of the same.

In order to set up the instrument the calendar disc is set at May 10th and the time disc to 9 hours, 23 minutes, which is the position in which the Alpha Star is at its meridian that is, directly above the North Star and will be observed at that particular day and hour through the slot 22 of the device when so set.

It may also be pointed out that the tube 12 is set at a slight angle to the true axis of the cylinder 7, the angle between the axis of the cylinder and the axis of the tube being 1 degree and 5 minutes (corresponding to the distance that the North Star is off centre) towards 1 hour and minutes on the time disc which indicates the stellar time at which the North Star reaches its meridian. The stellar time of (lassiopeias for-most star hereinafter reterred is hours minutes, North Star 1 hour 36 minutes and Ursa Major hours 59 minutes. These stars practically always maintain the aforesaid relation in all positions the amount of variation being infinitessimal.

In order to find the local time at any position on the earths surface the observer looks through the tube so as to observe the North Star therethrough. The handle 8 is then operated so as to turn the angular member 8 and the parts connected thereto circumterenti ally until the first star Alpha of the constellation Ursa Major commonly known as the dipper is seen through the slot 22. The pointer 23 will then indicate the correct time on the time disc 15.

In order to obtain the standard time of any place in which the observer is located, knowing that the earth turns 1 degree in 4; n'iinutes, and the longitude reading is multiplied by et and then divided into hours and minutes in the usual way.

From the local time found as above described and the standard time corresponding to Greenwich time which would be indicated by the observers watch the longitude of the locality can then be obtained. The number of minutes difference between the standard. and local. time is divided by 4, thus giving the number of longitude degrees. There is adifierence of 4 minutes between each degree, and by this means the exact longitude of any particular place is obtained.

In order to find the latitude all that the observer has to do is to swing the instrument on its t *ansverse axis formed by the pintles 5 and 6 until the North Star is observed through the tube 12, which is inclined as before set forth at angle of 1 5' to its true axis. The pointer 25 will then indicate on the scale 18 a true reading of the number of latitude degrees.

hen the Alpha Star is below the horizon the foremost star of the constellation Cassiopeia is used, this star being observed through the longitudinally slotted member 24, the device being then operated in the same way as above described.

At the end of each year the calendar disc is disengaged from the time disc and moved up a distance of a quarter day in order to take care of the extra six hours in the year. At leap year the calendar is moved back a day on February 28th, in order to compensate for the extra day.

What I claim as my invention is 1. An observation instrument comprising a cylindrical member, a pair of annular disc members surrounding the cylinder, the exposed face of one member being graduated into hours and minutes and the exposed face of the other member into months and days, a stationary pointer carried by the cylinder and coacting with the calendar scale, a pointer carried by the cylinder to move circumferentially therearouml and coacting with the time scale, a slotted member extending radially inward from the adjustable pointer and through which the star is observed as it travels in its orbit around the North Star, and a sighting tube mounted centrally in the cylinder and through which the North Star is observed.

2. An observation instrument comprising a cylindrical member, a pair of annular disc members surrounding the cylinder, the exposed tace of one member being graduated into hours and minutes and the exposed face out the other member into months and days, and means for securing the annular members together after being independently adjusted to the desired position.

37 An observation instrument comprising a sighting tube through which the North Star is observed, a cylindrical device in whicll the tube is revolvably mounted such device having its axis pointing to the centre of the North Stars orbit and adjustable to the daily travel of a predetermined star in its orbit around the North Star, an annular disc having time graduations therearound and. mounted on the cylindri al device, a member having a sighting orifice adjustable concentrically around the tube to conform to the varying daily position of such predetermined star, and a pointer carried by such member in radial alignment with the orifice to indicate the change in time on any particular day to which the device is set.

4:. An observation instrument comprising a base, a sighting tube through which the North Star observed, a cylindrical device mounted to swing on a transverse axis carried by the base and in which the sighting tube is mounted, and having its centre line extending at right angles to the transverse axis and pointing directly to the centre of the North Star orbit When the North Star is visible through the sighting tube, a pointer carried upon the swinging device, and a stationary graduating quadrant carried by the base with which the pointer coacts.

JAMES STEPHEN.

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