US2198710A - Stoker construction - Google Patents

Description

April 30, 1940. E. A. TURNER STOKER CONSTRUCTION 4 Sheets-Sheet 1 Original Filed Feb. 17, 1934 INVENTOR.

April 30, 1940. E. A. TURNER STOKER CONSTRUCTION Original Filed Feb. 17, 934

4 Sheets-Sheet 2 INVENTCR.

April 30, 1940. TURNER 2,198,71U

STOKER CONSTRUCTION Original Filed Feb. 17, 1954 4 Shets-Sheet s v11/11114 willy/l,

4 Sheets-Sheet 4 E. A. TURNER STOKER CONSTRUCTION Original Filed Feb. 17, 1954 v April 30, 1940.

INVENTOR.

Patented Apr. 30, 1940 j STOKER CONSTRUCTION Edwin Archer Turner, New York, N. Y., assignor, by mesne assignments, to The Standard Stoker Company, Inc., New York, N. Y., a corporation of Delaware Application 12 Claims.

My invention relates to stokers of the type which feed through an opening in an upright wall of a furnace and more particularlyto certain improvements in the construction of stokers for ino stallation toexisting locomotives in which the backhead of the firebox is provided with a firing opening of conventional form and size.

With the various types of stokers manufactured for installation on locomotives, it has been the experiencethat those which feed through the firing opening in the backhead of the locomotive possess many attributes of simplicity and economy of operation not found in many of the other types. Hence, the stokers of the general type described have found considerable favor with the railroads. However, there is one deterrent to the widespread installation of such stokers on existing locomotives, andthat is the cost of enlarging the firing opening so that the stoker may feed through the lower half thereof while the upper half is used as an inspection or hand firing opening. When the firing opening is enlarged, either a portion of or an entire backheadfis replaced ,by a new structure containing this en- 25 larged opening, This is a costly and a time consuming task, and the expense entailed in making this change must be charged to the ultimate cost of the stoker.

This deterrent is obviated by the present in vention which has for its main object the provision of an improved stoker of the class described adapted to feed through the conventional size of firing opening. It follows, of course, that the stoker may be utilized also with the larger openings.

Another and more specific object of this invention is to provide an improved stoker, as con templated by the main object of the invention, characterized by a compact, simplified and novel a) construction of the stoker discharge conduit and theassociated parts of the distributor apparatus whereby such parts occupy a minimum of space in the firing opening and afford free access into the firebox. A further object of this invention resides in the provision, in a stoker of the above described character, of a novel relation between the pressure fluid jet head, the distributing table and the stoker discharge conduit; the pressure fluid head being rigidly but detachably secured to the discharge "conduit, while the distributing table is interlocked with the conduit by a lug and groove connection permitting quick removal of the table from the firing opening whenever it is necessary February 1'7, 1934, Serial No. 711,642 Renewed April 8, 1938 for a workman to enter the firebox or for other reasons. 1

Other objects and advantages reside in the novel construction of the individual parts and in their relations one with another whereby a stoker is produced which may be installed on existing types of locomotives without changing the backhead or disturbing the accessories mounted thereon.

In the drawings accompanying the specification,

Figure 1 is a longitudinal sectional view of the rearward portion of a locomotive showing the invention in similar section with some portions in elevation and others broken away to illustrate the structure;

Figure 2 is a plan view taken on the line 2-2 of Figure 1;

Figure 3 is a View as seen from the interior of the firebox in Figure 1, looking in the direction of the arrows 3.-3;

Figure 4 is an enlarged sectional view taken on the line 4-4 of Figure 2;

Figure 5 is a view similar to Figure lshowing one modification of my invention;

Figure 6 is a rear elevational view taken on the line 6-6 of Figure 5;

Figure 7 is an enlarged sectional view similar to Figure 4 of a portion of the modification illustrated in Figure 5; 1

Figure 8 is a view similar to Figures 1 and 5 showing another modification of the invention; 1

Figure 9 is an enlarged sectional view similar to Figures 4 and 7 of a portion of the modification illustrated in Figure 8; and

Figure 10 is a view similar to Figure 4 showing 1 another modification of this invention.

Referring now to the preferred form of my invention illustrated in Figures 1 to 4, inclusive, l0 represents a locomotive, H the boiler thereof, and I2 the hollow backhead including the outer sheet l3 and the inner sheet I l. At a suitable distance above the cab deck 15 and the grates I6 of the firebox ll; the inner and outer sheets are flanged inwardly toward each other to form the conventional firing opening l8. This firing opening I8 is usually elliptical in shape and measures approximately sixteen (16) inches in height and twenty (20) inches in width, thereby affording free entry into the firebox. It is, of course, understood that in some instances these dimensions will vary.

The outersheet l3 of the boiler is'covered by lagging l9 whichis usually composed of magnesia and asbestos applied in sections or in plastic wall 39.

form. The lagging I9 prevents the loss of heat in the boiler through radiation. A jacket of planished sheet iron fits over the lagging and forms a protecting cover therefor. It will be observed from' Figures 1 and 2 that the lagging l9 and the jacket 20 terminate somewhat short of the outermarginal edge defining "the firing opening l8, leaving a portion of the outer sheet l3 adjacent the firing opening uncovered.

A fuel feed device for transferring fuel ream the tender to the locomotive is shownrgenerally as S and comprises a stoker riser or discharge conduit 2| on the locomotive andthe troughh'onduit 22 leading forwardly fromrthe tenderinot shown) and delivering to the"dischargeconduit 2| at a point below the cab deck 55, A universal joint connection 22a provides for-the flexibility necessary between the conduits 2| and 22 when the locomotive and tender are rounding curves or crossing switches and turntables.

The construction ofthe discharge-:oonduit-Zl is novel and will now be described in detail. 'It

comprises the casing 23 and the feedtube 32,

ing l8. A firedoor is supported from the casing 23 and forms a movable closure for the aperture 29. The firedoor illustrated is of the well known Franklin butterfly type having a motor M and a hand lever 3| whereby the firedoor may :be operated manually or by power means. It will be observed from Figure 1 that the uppermost edge of the arcuate top wall 26 is placedclose to the backhead l2 and ass.

consequence the firedoor operating mechanism does not extend outwardly from the backhead a distance which would interfere with hand firing, inspection of fire conditions or--entry into the firebox.

As the sidewalls 21 extend downwardly their outer marginal edges which are in the same inclined plane extend outwardly from-the backhead a greater distanceprogressively until at the lowermost point represented by-the edge 32a,

this point is spaced from the backhead'a horizontal distance which is approximately twice the horizontal distance from the uppermost edge of the upper wall 26 to the backhead. It will be observed the stoker feed tube 32slopesupwardly from beneaththe deck l5 at an angleapproximating 45 degrees and opens upwardly into the casing 23. The walls of the latter constitute con- 'tinuations of the tube 32 which is rigidly attached to the casing by means of bolts 33 passing through the flanges 34 and 35 of the casing and the tube, respectively. At its forward end, the tube 32 is securedto the backhead by means of bolts or studs 36 passing through the flange 31,

which is similar to the flange 25 of the casing 23 and in alignment therewith. If desired the casing and the tube may be integrally formed but for convenience of manufacture and assembly "it is preferred that they should be constructed separately as described to form the conduit 2 I,

The upwardly opening portion of the tube 32 includes side walls 38 which extend a slight distance into the firing opening l8 and curve toward each other to form the bottom or forward It will be observed that the central from the jet head 4|.

tion 55 is provided with a passage such as 51 for vertically drilled holes counter-bored as at 46.

Studs 41 are screwed into the flanges 68 formed with the bottom or forward wall 39 and the jet head-4| is seated on each flange so that the holes 45 thereof engage the studs 41. These flanges 48 do not extend across the width of the recess 40 but are formed only beneath each counter-bored portion 45. In this manner, the flow of cooling aircurrents beneath the jet head 4| is not restricted. Nuts 49 are utilized to firmly engage each stud, thereby securely, but detachably, holding the jet member in the recess. For convenience of assembly, the rearward end of the jet head 4| and the securing means therefon'lie between the vertical planes passed through the upper and lower. extremities of theaperture 29.

In the preferredembodiment of my-inventicn illustrated in Figures 1 to 4-.inclusive, a system of connected screws convey the fuel-from the tender to a point adjacent the firing opening. A screw 50 in the trough conduit 22 is flexibly connected to the screw 5| of the riser conduit 2| by a double universal joint 52 and this last named screwfil conveys the fuel along the bottomwall 39 and thence urges the same over the upper wall "53 of the jet head 4|.

The upper wall 53 0f the jet head has a lower portion 53: which forms an upward continuation of the bottom-wall 39, so that the fuel is urged along a smooth surface free of any irregularities, while the upper portion 53b of the jet head curves forwardly from the straight lower. portion and is disposedslightlyabove the lower marginal edge of the firing opening but below the lowermost edge of the aperture in the casing23. Preferably, the straight portion 531 is a tangent of the curved portion-53b and'by this a construction, together withthe relation existing between the bottom wall 39 and the-portion 53a, a free and easy passage for the fuel throughthe discharge conduit is provided.

As coal passes over the jet head 4|,it is subjected to a separation of the finer particles from the coarser particles and then. falls onto the upper surface 54 of the distributing table 55, from which it is projected to all parts of the firebed, in a manner which is now to be described.

Extending forwardly from the high pressure chamber or chambers 42 are the finger like projections 56 which are spaced apart and radiate Each finger-like projecemitting a blast of pressure fluid over the upper surface 54 of the table 55 and alsoover the low pressure blasts of pressure fluid issuing from the orifices 58 of the low pressure chamber or chambers t3. Thus, the larger lumps of fuel roll over the projections 56 while the finer particles sift through and fall in front'of the low-pressure orifices. The low pressure blast will spread the finer particles over the entire firebed, while the higher pressure blasts project the larger lumps forwardly. Ofcourse, some of the larger lumps of fuel will be acted upon by the "combined force of the high and low pressure blasts while some of the intermediate lumps of fuel will be acted upon solely by the low pressure blasts. This,

delivers fuel onto the distributing table at a rents and also must traverse a h 5 5 andiremoved from the damaging effects of the relatively higher point above the gratelevel than with stokers of former construction, and hence thelfuel as it is projected from the table 55 must pass through the more swiftly moving gas curgreater distance before falling on the grate.

So that the distributing table 55 may be easily renewed or removedfor the purpose of affording more space when entry into the firebox is made,

i i the curving side walls 38 ofthe discharge conduit are arranged todetachab ly support this member in a novel and advantageous manner. For this purpose, each side wall 38 at the forward end.

thereof is provided with an upwardly opening hook member 60 while the distributing table 55 is provided with the upwardly extending flanges 6| which form extensions of the curving side walls andhave formed therein the downwardly opening hook members 62 for engaging the hook members 60. Since the detachableconnection means between the table 55 and the discharge conduit is a substantial distance above the table heat in the firebox removal of the table will be facilitated and its life prolonged.

. Whenever access into the firebox is to be made,

pressure fluid is admitted into the chamber 63 at therear wall 64 of the discharge conduit and emitted through the forwardly directed passages 65, thereby removing anycoal which remains in the open mouth of this conduit. Thisremaining coal can also be pushed forwardly by manual means, thereby obviating the use of the blast chamber 63. The firedoor 30 is then opened preferably by hand and if the table extends into the firebox a distance which makes entry thereinto inconvenient, it may be unho oked and removed. Should it be necessary to remove the jet head 4|, a socket wrench may 'be fitted into the counter-bored portions 46 and 'the nut members 49 removed. The removal ofthe nut members 49 will not cause the jet head to fall fowardly into the firebox becausethestuds 41 effectively engage the drilled holes 45. Itwill be observed from Figure .1 that the jet head 4! when in .position in the firing opening is substantially below the lower marginal edge of the aperture 29 and is constructed so that it curves forwardly and upwardly to a point in the firing opening and then slopes downwardly. By such construction of the jet head, the upper surface thereof does not form a tunnel with the upper sheets of the firing opening, thereby. making possible freer access into the firebox. In certain instances, the i conduit, and a fuel distributing. table forward of said jet head, said fuel distributing table deupper chambers 42 will not be necessary and only the lower chamber 10, will be necessary.

This construction is shown in Figure 10 and it will be apparent that by the use of only the lower chamber or chambers 10, agreater effective firing opening will be available for entry into the firebox. 1 i In Figures 5, 6 and 7, thefuel feed tube comprisingthe discharge conduit is in the form of a forwardly and upwardly curving conduit member 1 I while the trough screw 12 terminates somewhat short of the forward wall 13 thereof and forces the fuel forwardly and upwardly over the jet head 4| and onto the, distributing table 55.

Otherwise, the construction of this modification is similar to the preferred form illustrated; in Figures 1 to 4, inclusive.

Another modification of the invention is illustrated in Figures Sand 9, and in this construction a fuel feedtube 14 extends upwardly along the verticalmedial plane of the fire-box and substantially parallel thereto. This tube 74 terminates below the level of the firing opening l8 and feeds upwardly into the lower extension l5 of the casing 76 which embraces the firingopening.

A casing of this form can also be used in the first two forms of my invention. .A trough screw ll in the conduit 18 feeds coal into therearward extension 19 of the tube 14. Thistube houses" a screw 8|] which is driven from its lower means of gearing 8| in the gear case 82. Since the casing 16 is provided with the integral lower extension 15, the recess 83 for thejet head 4| is.

formedin the lower extension of the casing instead of in the feed tube. The upper end of the,

screw 80 terminates below the lowermost edge of the aperture 29 so that it does not form an obstruction to hand firing or entry into the fire box.

From the foregoing description and illustrations of my invention it will be realized by those familiar with the problems encountered in the practical construction of locomotive stokers that many of these problemswhich exist are solved by the various novel features embodied herein.

' It will also be understood that the features of one type of stoker can also be used with stokers of other types, asdemonstrated herein. I de-.

fine my invention in the appfinded claims.

I claim:

1. In combination with a locomotive firebox having a firing opening in the backwall thereof, a fuel feeddevice delivering into said opening including a casing connected to said backwall and having topan d side walls partially surrounding the firing opening, the rearmarginal edges of said top and sidewalls lyingin a common inclined plane and being spaced? from said backwall todefine an aperture opposite said firing opening, the lowermost edge of said aperture be- Y ing spaced from said backwalla horizontal distance which is approximately twice the horizontal distance from the uppermost edge of said aperture to said backwall, a movable closure carried by said casing for suchaperture, a fuel feed tube extending upwardly toward and delivering into saidcasing. said tube and casing constituting a stoker discharge conduit, said conduit having a forward wall terminating adjacent the lower marginal edge of said firing opening and short of the forward wall to form a recess adjacent the lower portion of said firing opening, aypressure .fiuid jet head received in the recess formed between the aforesaid forward and side walls of said .tachably engaging said conduit above saidjet including a casing connected to said backwall said backwall, and side walls. extending beyond &

' and having topand side twarllspartiallyl surroun ing the firing opening the'rear marginal edges of said top and 'si'de' walls lyingin a" common inclined plane andbein'g"spacedfrom said backwall to define an apertur'e opposite said'firing 'opening, the lowermost edge of said aperture being spaced from said backwall a horizontal distancewhich is approximately twice thehorizontal distance from the uppermost edgeof said aperture to said backwall, a movable closure carried by said casing for-such aperture, a fuel feed tube extending upwardly towardsaid casing at an angle approximately 45*degrees from the horizontal and delivering into saidcasing, said tube and casing constituting a stoker discharge conduit, said tubehaving' a? forward wall terminating adjacent the lower marginal edge of said firing opening and short of said backwall, and side walls extending forwardly beyond said forward wall to form a recessacljacent the lower portion ofsaid firing opening, said side walls extending upwardly abovethe lower marginal edge of said firing open- 'ing'toform' continuations of the side walls of said casing, a pressure fiuid'jet head 'received in the recess formed between the aforesaid forward and side walls of said tube, a fuel distributing C table forward of said jet head deta'chably engaging' the side walls of said tube above said jet head, and a conveyor screw in said fuel'feed tube,

the forward end of said conveyor screw terminat ing adjacent the recessed portion of thet'ube and below the lowermost edge of the aperture in said casing; 1

-3."'In combination with a locomotive firebox having a firing openingin the backwall thereof, a-fuel feed device delivering into said'opening including a casing connectedto said backwall and having top and side walls partially surrounding the firing opening, the rear marginal edges of said top and side walls lying in a common inclined plane and'b'ei ng spaced from said'back:- wall to define an aperture opposite said'firing opening, the lowermost edge of said aperture being spaced from said backwall ahorizontal distance which is approximately twice the horizontal distance from the uppermost edge of saidaperture to said backwall, a movable closure for such aperture, a conduit, member curving forwardly and upwardly toward said casing and delivering thereinto above the lower marginal edge-of said firing opening, said conduit member and casing constituting a stoker discharge conduit, said co-n-,

distributing table engaging the sidewalls of said conduit member above said jet head.

4.- In combination with a locomotive firebox having a firing opening in the backwall thereof,v

a fuel feed device delivering into said opening including a casing connected to said backwall and having top and side walls partially surrounding the firing opening, the rear marginal edges of said top and side walls lying in a common plane and being spaced from said backwall' to define an aperture opposite said firing opening, the lowermost edge of said aperture being spaced rrom: said backwallsai horizontal distance": which --isr approximately twice the horizontal distance from the uppermostedge 'of said aperture to said :bachwall, a mov'able" closure for such aperture, saidlcas'inglhaving'a lower extensionterminating T :belowthelower marginal edge of said firing open- :ing,':said extension having a forward wall terminating-adjacent the lower marginal edge of said ifiring openingi andwshort of said backwalhthe side walls of said casing extending forwardly beyond'said forwa'rd wallya pressure fiuid jet head 'receivedlin the'recess formed between the aforesaid forward, and side walls of said casing, a fuel distributing tablej-forward'of said jet, said fuel distributing table detachably engaging the side walls of said casing above said jet head, a fuel feed tubeco'nnected to the lower extension of said casing and extending along: said backwall substantially parallel thereto, and a conveyor screw in said tube, the upper end of said conveyor screw terminating below the lowermost edge of the aperture in said casing.

5.- in a locomotive'having a firebox with a firing opening in the backwall thereof, the combination including a casing secured to said back- I wall 'said: casing having a top wall extending rearwardly from the upper marginal edge of said firing openingand side walls extending rear- Wardly from corresponding side marginal edges of such opening, a fuel feed tube communicating with said casing, said'fuel feed tube including a forward wall terminating adjacent the lower marginal edge of said firing opening and a rear wall'spaced-above the upper edge of the forward ,wall, the rear marginal edges of the top and side walls of said casing lying in a common plane and forming withthe upper edge of the feed tube rear wall a forwardly and upwardly inclined aperture oppositersaid firing opening, the forward wallaof said feed tube terminating intermediate t, the transverse vertical planes passed through the uppermost and lowermost marginal edges of said aperture, the transverse vertical plane passed I through the uppermost limit of said aperture passing closely adjacent the rearward lower marv ginal edge of said firing opening, the side walls of said tube forming 'continuations of theside walls of said casing and extending beyond said forward wall to form'a recess, a pressure jet head seated in said recess forming a continuation of the forward'wall of said tube, and means for detachably securing said jet head to said fuel feedtube, said means being disposed between the aforesaid vertical planes.

6. In a locomotive having a firebox with a firing'opening-"in the backwall thereof, the combination including a casing secured to said backwall, said casing having a top wall extending rearwardly from the upperrnarginal edge of said firing opening and side walls extending rearwardly from corresponding side'marginal edges of such opening, a fuel feed tube communicating with said firing opening and delivering into said casing, said fuel feed tube including a forward wall terminating adjacent the lower marginal edge of said firing opening and a rear wall spaced above the upper edge of the forward wall, the

rear marginal edges' of the top and side walls of i said casing lying in'a common plane and forming with the upper edge of the feed tube rear wall a forwardly and upwardly inclined aperture opposite said firing opening, the forward wall of said feed tube terminating intermediate the transverse verticalplanes passed through the uppermost and lowermost-marginal edges of said aperture, thetransverse vertical'plane passed-through the up to formsa recess, ,apressure jet head seated in said recess forming a continuation of the forward wall of said tube, and means disposed between the aforesaid vertical planes for detachably securing said jet head to said fuel feed tube, said means including a threaded projection carried by said tube and engaging said jet head, and a threaded member engaging said threaded projection.

7. In a locomotive having a firebox with a firing opening in the backwall thereof, the combination including a casing secured to said backwall, said casing having a top wall extending rearwardly from the upper marginal edge of said firing opening and side walls extending rearwardly from corresponding side marginal edges of such opening, a fuel feed tube communicating with said firing opening and delivering into said casing, said fuel feed tube including a forward wall, terminating adjacent the lower marginal edge of said firing opening and a rear wall spaced above the upper edge of the forward wall, the rear marginal edges of the top and side walls of said casing lying in a common plane and forming with the upper edge of the feed tube rear wall a forwardly and upwardly inclined aperture opposite said firing opening, the forward wall of said feed tube terminating intermediate the transverse vertical planes passed through the uppermost and lowermost marginal edges of said aperture, the transverse vertical plane passed through the uppermost limit of said aperture passing closely adjacent the rearward lowermost edge of said firing opening, the side walls of said tube forming continuations of the side walls of said casing and extending beyond said forward wall to form a recess, a pressure jet head seated in said recess forming a continuation of the forward wall of said tube, and means disposed between the aforesaid vertical planes for detachably securing said jet head to said fuel feed tube, said means including a threaded projection carried by the forward wall of said tube closely adjacent said recess, such threaded projection freely enaging said jethead, and a threaded member engaging said threaded projection.

8. In a locomotive having a firebox with a firing opening in the backwall thereof, the combination including a casing secured to said backwall, said casing having a top Wall extending rearwardly from the upper marginal edge of said firing opening and side walls extending rearwardly from corresponding side marginal edges of such opening, the rear, marginal edges of said top and side walls lying in a common inclined plane spaced from said backwall, a fuel feed tube communicating with said firing opening and delivering into said casing, said fuel feed tube including a forward wall terminating adjacent the lower marginal edge of said firing opening and a rear wall spaced above the upper edge of the forward wall, the rear marginal edges of the top and side walls of said casing lying in a common plane and forming with the upper edge of the feed tube rear wall a forwardly and upwardly inclined aperture opposite said firing opening, the forward wall of said feed tube terminating intermediate the vertical planes passed through the uppermost and lowermost marginal edges of through the uppermost limit of said aperture passing closely adjacent the rearward lower marginal edgeof saidflring opening, the side walls of i said tube forming continuations of the side walls of said casing: and extending beyond'said said aperture, the transverse vertical 'planepassed' forward wall tocform a recess, a pressure jet head 9 seated insaid recess forming a continuation of the forward wall of said tube, and vertically disposed fastening members detachably securing said jet head to said fuel feed tube, said fastening means being disposed between the aforesaid vertical planes.

9. In combination with a firebox having a wall with a firing opening therein, a stoker discharge conduit communicating with said firing opening, a pressure fluid jet head secured to .said conduit, a distributing table extending forward of said jet head and having a fuel supporing upper surface, a flange at the rear of'each side of said table extending above the fuel supporting surface thereof rearwardly to a point beyond the lateral limits of said surface, the rearward end of ,each flange being provided with a hook member opening downwardly, and means providing an upwardly opening hook member at each side of said conduit, the downwardly opening hook members of said distributing table being adapted to engage the respective upwardly opening hook members adjacent the sides of said conduit and cooperating to support said distributing table in a predetermined relation with said jet head, said hook members; being engageable with and disengageable from each other upon downward and upward straight line movement, respectively, of said distributing table.

10. As an article of manufacture, a distributing table having a fuel supporting surface disposed substantially in a horizontal plane when said distributing table is in its operative position, and a fiangeextending outwardly from each side of said table and at one end thereof to a point above the fuel supporting surface and beyond the lateral limits thereof, each flange being provided with a downwardly opening hook member in a plane above the fuel supporting surface, said flanges and fuelsupporting surface defining an upwardly opening channel at one end of said table for constraining fuel therein.

11. In combination with a firebox having a wall with a firing opening therein, a stoker discharge conduit provided with a mouth portion communicating with said firing opening, a pressure fluid jet head mounted at the bottom of said mouth portion, a distributing table forward of said jet head and having a fuel supporting upper surface, a flange at each side of said table extending upwardly and rearwardly above the fuel supporting surface thereof, the rearward end of each flange being provided with a hook member opening downwardly, and means providing an upwardly opening hook member at each side of said conduit, the downwardly opening hook members of said distributing tables being adapted to engage w the respective upwardly opening hook members table for astoker having a fuel supporting-surface disposed substantiallyin a horizontal plane when said distributing table is in its operative! position, and a flange extending upwardly from each side of said table and at one end thereof defining with said fuel supporting surface an.

upwardly opening channel at' the said end of the table forponstraining fuel therein, said \a downwardly opening hook member in a plane above thefuel supporting surface.

E. ARCHER TURNER.

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