US1900117A - Sundial - Google Patents

Description

March 7, 1933.

F. LO RIA J 17 SUNDIAL Filed March 15; 1928 4 Sheets-Sheet 1 March 7, 1933.. LQRIA 1,900,117

SUNDIAL Filed March 13; 1928 4 Sheets-Sheet 2 March 7, 1933. i F. LORIA SUNDIAL v Filed March 13, 1928 4 Sheets-Sheet a March 7, 1933. F. LORIA SUNDIAL Filed March is, 1928 '4 Sheets-Sheet 4 Patented Mar. 7, 1933 ma- STATES PATENT sewer FRANCESCO LORIAQOF ROME, ITALY sUnDIAL Application filed March 13, 1928, Serial. No. 261,335, andin Italy January 14, 1928.

The Sundial in accordance with the present nventlon is provlded' with a hearing which permitsit to be easilysetup or taken to pieces, and which permits setting it promptly t Fig. 1, which showsthe goniometer and the .55

f to the necessary latitudeand properly orientating it with'respect to the meridian of the of which indicates the time from December I place. This bearing is also provided'with a device which permits correcting the position of the sundial in order to permit itto coincide with the meridian, ofanother place. I

All these operations required till now a long time and above all a knowledge of the cosmography, whilst with the sundial in accord ance with the present invention the operations may be carried out in a short time,owing to the simplicity of the device;

As the hour lines at theaverage time are curved like the form of the figure .8, whose widest part reaches a space of more than minutes, the consequence is thatthe signs of r the quarters of an hour, and also ofthe halves of an hour, would intersectone another and thus produce confusion. In order to avoid this inconvenience the'present invention pro-- vides the use of two series of hour indicia, one

21st to June 21st and the otherthe time from June 21st to December 21st, Each of these series is formed by two circular plates having the form of a cup, whose-hour lines may be applied on each face of the disc. which constitutes the sundial,'so that for each one of the two faces there are two plates. One plate will bear for instance the hour 'llIlQS'fIOIIl March 21stt0 June Qlstand the other, the hour lines fromtlune 21st to SeptemberZlst. In the same'way another plate will bear the indications from SeptemberQlst to December 21st, and the last plate will bear'the hour lines from December 21st to March 21st.

The invention will be understoodfrom the following specification, which refers to the annexed drawings 111' which:

w 1 Fig. l-is a front view of'the universal sundialin accordance with the inventlon, whlch 1s supposed to be placed vertically, viz. at the Equator with theplate marked for the period from March 21st to June 21st. 1

Fig. 2 is an axial section of the sundial sup- I posed to be inclined at the latitude of 42.

{Fig.3 is a sea view of the sundial with the plate niarkejd for the period from une 21st to September 21st.

the line AB of Fig. t is 'as'ection along pointer orsetting the sundial' under the meridian used. I

Fig. 5 is aplan in accordance with the section C1.D;of Fig. 2.

Fig. 6 isa partial view on In the Northern Hemisphere the two plates March 21stSeptember',2lst must beplaced on the upper face of the disc, and the other two, September 21st.;to March, 21st, on the lower face. The contrary must be done if the sundial is set up in the Southern I-Iemisphere. v p

The apparatus is'made up of atriangular base -1 to be hired on supports or pillars made 'with, bricks, stone, iron or Wood and which carries-at its centre a pin 2-whose end is threaded and't'o' which a nut 3 is screwed in order toseoure'in place a frame to be fixed I on a plate or supporting member 4 after this plate has been placed exactly horizontally.

In the c'entreof said. frame is arranged a shaft or uprightbearerrj, which may turn on its axis and which carriesin equilibrium at its top, in 5, an arm 6 which is fixed to the disc? 'ofthe sundial. The centre of the disc 7 is crossedby a stylefl8 which extends nor- '90 1nally-to"the two'faces of the disc,"and on these faces,as well as on the inclined borders 9, 10 of the disc, arearranged plates onwhich are marked the hours, the halves of an hour and the three qualrtersof'anhour, at the average time,'which are indicated exactly'by the shadowofthe style. v In order to set up the apparatus it is before all necessary to'place the triangular base'l onitsbasement, taking care that one of the the sideof the 60 Sundial, which shows the goniometer'for setangles be directed by approximation north. 4

towards The frame is then put in place by introducing the plate 4 upon the pivot 2 of the base and by directing the point towards the north or the south according to circumstances. T ienut 3 is put on the pivot 2 without screwing it completely up; the plate t is perfectly levelled in all directions and afterwards the nut 8 is screwedup until it adheres to the plate 4. When this has been done the shaft 5 is placed into the frame and on this shaft is arranged the disc 7 already provided with its season plates.

In order to place the sundial at the latitude of the place one proceeds as follows.

If the geographical latitude of the place is known, it is suiiicient to turn the disc 7 on its pivot 5, until the corresponding degree marked on the goniometer 16 arranged on the arm 6, coincides with the axis of the shaft 5.

Figs. 2 and 6 represent for instance the sundial at the latitude of 42. The disc is then fixed by screwing up the two screws 17 17 near the shaft 5, until the two segments of circle 16 are fixed firmly to the said shaft.

When the latitude of the place is not known 7 the disc must be directed towards the sun and at midday it must be put in such a position that the shadow of the style fails on the day circle corresponding to the day of the operation. For instance, if the day is April 13th, the disc must be put in such a positlon that the shadow of thestyle falls on the circle of- April 13th. When this has been done, the sundial is placed at the latitude ofthe place and the goniometer 16 will give the corresponding indication. I

, In order to place the sundial under the meridian, one proceeds as follows.

The slate 11 with its small rod 12 is put on the south part'of the plate, and after having' levelled it in every direction, from a small hole13 which is arranged in the upper part of the rod 12 a plumb 14 is dropped in a vertical direction and the resulting .point is marked. This point is taken as the centrefor describing two or three arcs of a circle as large as the slateallows. One now observes when the ray of light proj ccted by the small hole crosses each one of these arcs by passing into and out of the area of the slate, and in the spots thus obtained points are marked. The two points of every are are connected by a line and these lines are divided at their centre and from these points a line is drawn passing through the vertical from the small hole and this line is the meridian line of the place. On the following day, when the ray from the small hole is about to approach to the meridian line, one observes it and when it is exactly on that line, one arranges so that the shadow of the style in its turn falls exactly on the NS line of the disc. Afterwards the binding clamp 15 must be screwed up at the foot of the shaft 5 and the sundial will be fixed under the meridian of the place.

In order to place it under the meridian of another place, it is sufficient to displace it by as many degrees as it is away from the first place. The scale 18 placed on the upper face of the frame serves for this purpose in co operation with the hand 19 fixed to the shaft 5. It is to be noticed that if the meridian of the new place is eastward the displacement is to be made towards the eas't, whilst if the meridian of the new place is westward the displacement is to be made towards the west. r

In sundials of great size, the day circles on the different circular plates'may be marked for every day, instead of for a period of days, as for the sake of simplicity it has been shown on the drawings, and in this case the sundial may also form a calendar.

What I claim is: i v

1. In an instrument of the class described, a supporting member, an upright bearer upon said member, an arm mounted for tilting adj ustment upon the bearer, two cup-shaped discs mounted upon the arm at their axes and in opposition to each other, the relatively re ;mote faces of the discs bearing indicia indicating hours and fractions of hours, the

angular adjustment of the arm permitting.

either disc to be positioned to receive rays from'the sun, a style at the axes of the discs projecting at its end portions beyond. the the faces of the disc whereby to provide for the casting of its shadow, under the sunlight rays, onto the'respective face ofthe respective disc, the bearer being rotatable for adjustment of the discs in accordance with the adopted meridian, and means for holding the bearer in its positions of adjustment.

2. In an instrument of the class described, a supporting member, an upright bearer upon said member, a disc mounted upon the bearer for angular adjustment wherebyit may be inclined in accordance with the latitude of the place where the instrument is to be used, the disc bearing upon its face, indiciaindicating hours and fractions of hours, a style' positioned axially of the disc to cast its shadow, under sunlight rays, on to the face of the disc the bearing being rotatable for adjustment of the disc in accordance with the adopted meridian, means for holding the bearer in its positions of adjustment, a slate mounted upon the supporting member opposite the bearer, and a plumb suspended above the said slate. I

3. In an instrument of the class described, a supporting member, an upright bearer upon said member, a cup shaped disc mounted upon the bearing member for angular adjustment whereby it may be inclined in accordance with the latitude of the place Where the instrument is to be used, the bearing member rotatable, means for holding the member in positions of rotative adjustment, means in juxaposition to the bearing member and bearing a scale concentric to the axis of rotation of the said member, a pointer carried by the said bearing member, the disc bearing upon its face, indicia indicating hours and fractions of hours, and a style positioned axially of the disc to cast its shadow, under sunlight rays, on to the face of the disc.

In testimony whereof I have aflixed my signature.

FRANCESCO LORIA.

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