US784986A - Barometer. - Google Patents

Description

PATENTED MAK 14, 1905.

L. F. CHAN BY.

BAROMETBR.

APPLIGATION FILED sEPT.12.19o4.

W f TNESS INVENTORY;

` zomey l No. reggae I UNITED STATES Patented March 14, 1905.

PATENT OFFICE.

LEE F. OHANEY, OF LYNCHBURG, OHIO, ASSIGNOR OF ONE-HALF TO RILEY S. CHANEY, OF LYNCHBURG, OHIO.

BAROIVIETER.

SPECIFICATION forming part of Letters Patent No. 784,986, dated rlarch 14, 1905.

Application med september 12, 1904. seria at. 224,203.

T0 all 'l1/7mm t may cm2/cern:

Bc it known that I, LEE F. OHANEY, of Lynchburg, in the county of Highland and State of Ohio, have invented certain new and useful Improvements in Barometers; and I hereby declare that the following is a full, clear, and exact description thereof, reference being' had to the accompanying' drawings, which form part of this specification.

This invention is an improvement in barometers; and it consists in the novel features of construction thereof hereinafter described and claimed.

Vln the accompanying drawings, Figure l is a longitudinal section through the preferred form of the barometer. Fig. 2 is a sectional View through a slight modification of F ig'. 1. Fig. 3 is a sectional View, and Fig. 4 isaside View, of another modification. Fig. 5 is a transverse section on line 5 5, Fig. l.

Each of the barometers shown comprises an outer glass casing, an internal mercury-tube, the lower end of which is closed byamercury seal in a chamber, and a capillary air-tube which connects the mercury seal with the atmosphere. There are certain differences in the details of construction of the various barometers shown, which I will point out in the detailed description thereof.

Referring to Figs. l and 5, the outer cylinder or casing A is preferably made of glass, and its upper end is contracted and provided witha suspending' cord or device @which may be of any suitable kind. The bottom of the cylinder may be closed, as hereinafter eX- plained.

Located axially within the casing is a mercury-tube B, which is centered in the casing by spiders or corks O C C2 C3, I shall refer to them as corks7 hereinafter, but do not limit myself thereby to the material cork, as any suitable substance may be used.

The space between the corks C O forms an air-chamber D, communicating with the atmosphere through a capillary tube E, which may have a very fine bore, and the bore may, if desired, be filled with an air-filtering material, as at c, The tube B does not communicate with chamber D, but extends below cork Gand opens into a chamber (Z between cork C and a bottom cork or plug c, closing thelower end of the casingair-tight, as shown, the air-tube E, however, passing through cork c. The chamber Z should be filled with mercury and also the tube B, and chamber (Z communicates with chamber D through a minute passage Z/ in the cork C, which passage may bc a small g'la ss tube, and when the mercury drops in the barometer-tube B it can overflow from chamber CZ into chamber D through said passage d. Preferably an excess otl mercury may be maintained in chamber D suflicient to insure the constant maintenance of the supply in chamber (Z.

The glass tubing (hard or soft) from which the barometer is made may be of any desired diameter and about nine hundred millimeters in length. The outer tube A, which forms the casing, or the inner tube B, which contains the mercury, is to have a scale etched on itin either the English or metric system. The scale is so constructed so as to give an exact reading without adjustment. The scale may reach full length of the barometer or be graduated for a space at the top and at the bottom, with an intervening space between.

As shown in Fig. l, the tube is etched with a scale, as indicated at a', and in Fig. Q the casing is etched with a scale, as indicated at Either or both the tube B or casing A may be provided with a scale; but it is not necessary to have a scale on both. The scales may be continuous,if desired, or the interu'lediate portions (which are seldom used) may be omitted, as indicated in Fig. 4.

The air which causes the action of the barometer passes through the tube E, up through the mercury to the top part of the chamber D, which communicates with the chamber d, that contains the mercury in which the lower end of the tube B, containing the column of mercury. is immersed. The cork c is further used to stop the end of the tube B, containing the column of mercury, for by pushing' the plug or cork up against the end of the inner tube B it will keep the mercury from escaping' from it and prevent the entrance of air to the inner tube during transportation.

The cork has a recess c in the end of it for the inner i ing thelevel ot' the mercury to acertain point;

tube to it into when pressed up ag'ainst it to prevent the escape of mercury from the inner tube or intrusion o't' air.

The barometer may be placed in any position without danger of loosing the mercury Jfrom the mercury-chamber. Air-bubbles can be removed from the tube containing' the column of mercury by causing' an air-bubble of suiiicient size to traverse the length ot' the tube a few times. The barometer is inverted and by an up-and-down motion the inner tube is {illed full otl mercury. Cork e is then pressed down till it closes the inner tube. The barometer is then held in' an upright position, and cork c is pulled away 'from the end of the inner tube and the barometer is in working order.

As shown in Fig. 2, a screw-closure F is tapped through plug' @and can be adjusted so as to close passage (W, and when this passage is closed the tube and chamber (l are both sealed. The barometer shown in Fig. Qis the same as that in Fig. i with the exceptions noted.

These mercurial barometers are so constructed that the lower chamber (Z is always iilled entirely with mercury, the lowei' chamber being' connected with the top chamber D by a capillary opening or tube J, which will -not allow the mercury to escape from the lower chamber and air to enter at the same time on account ot' capillary action. The expansion and contraction of the mercury in the lower chamber and inner tube due to heat and cold is provided for by the corks forming the top and bottom oiE the lower chamber' and which close it air-tightly when the screw or plug tits in the opening between the two chambers. them farther apart and vice versa. '(See Figs. l and 2.) The pressure of the air forces the corks back when the mercury contracts.

In Figs. 3 and 4 the construction is sliglitly different from that in Figs. l and 2 in that instead of the two chambers l) one large chamber 1.) is employed.

The ad van tages of my barometer over those heretolore known: lirst, simplicity ol construction; second, compactnessol form; third, the ease with which it can be handled without vtear of it getting' out oi order or breaking, the capillary tube not permitting ot a rapid change ot' the mercury from the upper to the lower chamber when the barometer is held in a horizontal position and the mercury ills the inner tube, which, it it were not for it passing through the capillary tube, would rush into the inner tube with such torce as to break the inner tube, which is a fault of other barometers; fourth, the scale being etched from Zero (O) to eight hundred millimeters and downward twenty millimeters vfrom zero, an accurate reading' can be had without adjust- The expansion of the mercury 'forces' but by adding or subtracting the distance the mercury in the mercury-chamber happens to be below or above the Zero (O) mark to or from the height ot the mercury in the inner tube, as indicated on the scale thereon, gives an exact reading of the height ot' the column of mercury; fifth, the barometer having the scale as described is better adapted for the use of the physicist than the usual iorm, as it can be placed in a partial vacuum and correct readings can be taken at any time during the operation by the method be't'ore given. l

Having' thus described my invention, what I claim as new, and desire to secure by Letters Patent thereon, isn

l. In a barometer the combination o't' two communicating' mercury-chambers, an airpassag'e communicating with one chamber, and a mercury-tube passing' through the latter chamber into the other chamber and sealed by the mercury therein, substantially as described.

2. ln a barometer, the combination of two communieating'mereury-chambers,amercurytube communicating' with one chamber and sealed by the mercury therein, and an air-tube extending through such chamber and opening' into the other mercury-chamber, substantially as described.

8. ln a barometer two communicating mercury-chambers adapted to provide for the eX- pansion and contraction otl the mercury, a mercury-tube passing through one chamber and communicating' with the other chamber and sealed by the mercury therein, and an airpassag'e to that mercury-chamber through which the tube passes, substantially as described.

4. In a barometer, the combination of the` casing', having a pair of connected mercurychambers, a mercury-tube passing through one chamber and connecting with the other, and an air-passage connecting' with that mercuiy-chamber through which the tube passes, all constructed and adapted to operate substantiall y as described.

in a barometer, the combination ot the glass casing', having a pair of connected chambers, a mercury-tube passing' through one chamber and connecting' with the other, and an air-passage connecting' with that mercurychamber through which the tube passes, and means For closing' the connection between the chambers, substantially as described.

In testimony that I claim the foregoing as my own l aiix my signature in presence of two witnesses.

LEE F. CHANFY.'

1n presence ofA Anom HAAR, l J. H. lYLinQUAuD'r.

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