Full text of 'RP 142THE RING AND BALL METHOD OF TEST FOR SOFTENINGPOINT OF BITUMINOUS MATERIALS, RESINS, ANDSIMILAR SUBSTANCESBy Percy H. WalkerABSTRACTThe softening point of materials which, like asphalt, have no definite meltingpoint, but which when heated gradually change from brittle or very thick andslow-flowing materials to more mobile liquids, can only be determined by somearbitrary method. The ring and ball method which briefly consists of determin-ing the temperature at which a disk of the material held in a ring and loaded witha ball will flow through a definite distance when heated at a prescribed rate is oneof the best methods for such tests. Published directions for making the test are,however, open to very serious objections, and this paper describes the apparatusand procedure used at the National Bureau of Standards. The principal modi-fications in the apparatus are a beveled instead of a cylindrical ring, and acentering device for the ball. The procedure is so described that some latitude innonessential details is permitted.CONTENTSPageI. Introduction 195II.
Apparatus 1961. Container 1984. Thermometer 1995. Support for ring and thermometer 199III. Preparation of sample 199IV. Procedure 1991.
AIM: To determine the softening point of asphaltic bitumen and fluxed native asphalt, road tar, coal tar pitch and blown type bitumen as per IS: 1205 - 1978. PRINCIPLE: It is the temperature at which the substance attains a particular degree of softening under specified condition of the test. APPARATUS: i) Ring and ball apparatus. Nov 09, 2015 EXPERIMENT NO. 12 SOFTENING POINT OF BITUMEN (RING-AND-BALL APPARATUS). ASTM Designation: D 36-76, AASHTO Designation: T 53-89SOFTENING POINT: Softening Point of Bitumen. The softening point is defined as the mean of the temperatures at which the bitumen disks soften and sag downwards a distance of 25 mm under the weight of a steel ball.
Bituminous materials, resins, etc., having softening points80° C. Or lower 2002. Bituminous materials, resins, etc., having softening pointshigher than 80° C 200V. Typical determinations „.
INTRODUCTIONThere are many materials which, like asphalt, have no definitemelting point, but which when heated gradually change from brittleor very thick and slow-flowing materials to softer or more mobileliquids. For such materials the ring and ball method is a valuablemethod of test. Briefly, this test is a determination of the tempera-ture at which a disk of the material held in a ring and loaded with aball will flow through a definite distance when heated at a prescribedrate. However, it is an arbitrary method and in order to get agreeingresults a fixed, arbitrary, and closely defined method must be used.The method is best known to laboratories that test asphalt, andthe A.
T.M.inl916 adopted a tentative description of the method,amended this and adopted it as standard in 1919, and has sincerevised it several times, the latest revision being in 1926 under serialdesignation D36-26. Standards, Pt. 496; 1927.195196 Bureau of Standards Journal of Research ivoi.4The A.' Specifications for this test are open to the followingobjections:1. The apparatus as described is not used, nor can it be easily usedto meet the rigid requirements given in the text. For example, thering is supported on one side by a brass wire 1.83 mm in diameterwhich is supported in a cork held in a clamp, and this must be placedexactly 2.54 cm above the bottom of the beaker and 5.08 below thesurface of the water.2. Tolerances are given for inside diameter and thickness of thering, but not for its depth.3.
The method is limited to asphalts, while if properly describedit can be used with numerous materials.4. The cylindrical ring specified limits its use to materials likeasphalt that do not shrink away from the ring.
A slightly beveledring gives with asphalts the same results as the cylindrical ring andhas the distinct advantage that it can be used with resins and pitcheswhich may shrink away from the cylindrical ring.5. Method prescribes unessential limitations in thekind and set-up of apparatus, while there is not reason why a numberof different forms of apparatus can not be used provided they allcomply with certain requirements.Hence, it seems desirable to describe the apparatus and method asused at the Bureau of Standards.II.
APPARATUSThe essential apparatus is as follows:1. RINGA brass ring of the following dimensions:Depth.— 6.35 ±0.10 mm (ft inch).Inside diameter at bottom. 88 ±0.10 mm (% inch).Inside diameter at top.
— Not less than inside diameter at bottomnor more than 17.6 mm, preferably 17.46 mm (% inch).Outside diameter at bottom. — Not less than 18.0 mm nor more than21.0 mm.Outside diameter at top.
— Not less than outside diameter at bottomnor more 21.0 mm.The interior of the ring may be either tapered, within the toler-ances given above, or cylindrical. (The tapered ring is to be preferred,as it can be used with all kinds of materials to which the ring and ballmethod is applicable. The cylindrical ring, while suitable for asphalts,can not be used with materials that shrink away from the ring, suchas resins and pitches.)The outside of the ring may be either uniformly cylindrical orsmaller at the bottom provided the above dimensions are compliedwith. For convenience in mounting it is advisable to have it smallerat the bottom. BALLA steel ball, such as used in ball bearings, 9.53 mm (% inch) indiameter weighing between 3.45 and 3.55 g.walker Test for Softening Point of Bituminous Materials, Etc. 197198Bureau of Standards Journal of ResearchVol.!3. CONTAINERA glass vessel, capable of being heated, not less than 8.5 cm (3%inch) in diameter and not less than 10.5 cm (4% inches in depth fromthe bottom of the flare.
(A 600 ml beaker, low form.)4. THERMOMETERFor materials having softening points not above 100° C. A totalimmersion thermometer meeting the specification given in item 5331(d) of General Schedule of Supplies, Fiscal Year 1930, is used. 2For materials having softening points above 100° C. And below300° C. A partial immersion thermometer meeting the specificationgiven in item 5331 (b) of the General Schedule of Supplies may beused. 3Diameter, 6.0 to 7.0 mm.Length, 20 to 30 mm.
Diameter, not2 This specification is as follows:Type. — Etched stem, glass.Liquid. — Mercury.Range and subdivision. — Minus 4° to +104° C.
In 0.2°.Total length. — 454 to 460 mm.Stem. — Plain front, enamel back, suitable thermometer tubing.Bulb. — Corning normal or equally suitable thermometric glass.greater than stem.Distance to —4° line from bottom of bulb.— 50 to 70 mm.Distance to +104° line from top of thermometer. — 20 to 50 mm.Filling above mercury. — Nitrogen gas.Top finish. — Glass ring.Graduation.— All lines, figures, and letters clear cut and distinct.
Lines corresponding to even degreemarks to be longer than the remaining lines. Graduations to be numbered at each multiple of 2°.Immersion.
— Total.Scale error. — The error at any point of the scale, when the thermometer is standardized at total immersion,shall not exceed 0.3°.Special marking.— A serial number and the manufacturer's name or trade-mark shall be etched on thestem.Case. — The thermometer shall be supplied in a suitable case, on which shall appear '—4° to +104° C.in 0.2°, total immersion.' 3 This specification is as follows:Type. — Etched stem, glass.Liquid.
— Mercury.Ranges and subdivisions. — Minus 5 to +300° C. In 1°.Total length.— 379 to 383 mm.Stem. — Plain front, enamel back, suitable thermometer tubing. Diameter, 6 to 7 mm.Bulb. — Corning normal or equally suitable thermometric glass. Length, 10 to 15 mm.
Diameter, 5 to6 mm.Distance to 0° line from bottom of bulb.— 90 to 100 mm.Distance to 300° line from top of stem. — 25 to 50 mm.Filling above mercury. — Nitrogen gas.Top finish.— Glass ring.Graduation.— All lines, figures, and letters clear cut and distinct. The first and each succeeding 5° lineto be longer than the remaining lines. Graduations to be numbered at each multiple of 10°.Immersion.
— The words ' 76 mm immersion ' and a line around the stem, 75 to 77 mm above the bottomof the bulb, shall be etched on the thermometer.Special marking. — A serial number and the manufacturer's name or trade-mark shall be etched on thestem.Scale error.— The error at any point of the scale, when the thermometer is standardized as providedbelow, shall not exceed 1°.Standardization. — The thermometer shall be standardized for 76 mm immersion and for the followingtemperatures of the emergent mercury column. These stem temperatures have been chosen as correspond-ing, on the average, to those likely to occur in the use of the thermometer:Thermom-eter readingAveragetemperatureof emergentmercurycolumn961707680Case.— The thermometer shall be supplied in a suitable case on which shall appear the marking: '-5° to+300° C., 76 mm immersion.'
Partial-immersion thermometer for general use —5° to 300° C., D-183-25 meets thisspecification.walker Test for Softening Point of Bituminous Materials, Etc. Thermometer (seeA. D-36-26) gives within its range readings identical withthe -4° to + 104° C.
Thermometer specified above. P., +30° to 160° C. Thermometer (D-36-26) will read veryslightly higher than the —4° to +104° C.
Total-immersion thermom-eter, the difference being less than 0.3° at 80° C. And about 0.3° or0.4° at 100° C. The partial-immersion thermometer gives truetemperature readings which as compared with the total-immersionthermometer (used for partial immersion as in this test) will beabout 0.6° to 0.7° higher at 80° C.
And 1.0° to 1.1° higher at 100° C. SUPPORT FOR RING AND THERMOMETERAny convenient method for supporting the ring may be usedprovided it meets the following requirements: The ring must besupported in a substantially horizontal position; the top of the ringmust be at least 8 cm below the top of the container and the bottomof the ring 2.54 ±0.02 cm (1 inch) above a horizontal plate or thebottom of the container; the distance from the center of the ring tothermometer bulb must be not more than 16.5 mm.A device for centering the ball is desirable, but not essential.III. PREPARATION OF SAMPLEMelt the sample and stir it thoroughly, avoiding incorporatingair bubbles in the mass, and then pour it into the ring so as to leavean excess on cooling. The ring while being filled should rest on abrass plate that has been amalgamated to prevent the sample fromadhering to it. After cooling, cut off the excess material cleanlywith a slightly heated knife. Determine the softening point withinthree hours after the sample is prepared.IV.
BITUMINOUS MATERIALS, RESINS, ETC., HAVING SOFTENINGPOINTS 80° C. OR LOWERFill the glass container to a depth of not less than 9 cm with freshlyboiled distilled water that has been cooled to not less than 45° C.below the softening point of the material under test, provided suchsoftening point is not below 50° C. If the softening point is below50° C. The water shall be cooled to not above 5° C. Place the filledring and ball, but not in contact, in the bath and maintain the initialtemperature for 15 minutes. Then place the ball in the center ofthe upper surface of the material in the ring, and at once suspendthe support carrying the ring, ball (ball guide if used), and horizontalplate so that the top of the ring is not less than 5.1 cm below thesurface of the water and the —4.0° to +104° C.
Thermometer ishanging approximately in the middle of the container. The figureshows details of ring, ball guide, support, container, and assemblyof apparatus except tripod and burner. Apply heat in such a man-. The use of a total-immersion thermometer for materials of low softening points and of partial-immersionthermometers for materials of higher softening points is recognized as a disadvantage; but the thermometersselected appear to be the best available in their respective ranges, and their use avoids the introductionof new and special thermometers for this work,200Bureau of Standards Journal of ResearchVol.
4ner that the temperature of the water after the first three minutesof heating is raised uniformly 5.0° ± 0.5° C. To facilitateuniform heating, it is advisable to place the burner midway betweenthe center and the edge of the beaker away from the specimen.Report as the softening point the temperature indicated by thethermometer (adding or subtracting any certified corrections, butmaking no emergent stem corrections) at the instant the sampletouches the horizontal plate or the bottom of the container.2. BITUMINOUS MATERIALS, RESINS, ETC., HAVING SOFTENINGPOINTS HIGHER THAN 80° C.Use the same method as given under IV, 1, except that instead ofwater a suitable bath shall be used, and with materials having softeningpoints above 100° C. The — 5° to 300° C. Partial-immersion thermometershall be used. Glycerine is suitable for asphalts and unlessotherwise specified shall be used. When the nature of the materialtested indicates that glycerine is not suitable, other liquids, air, orinert gases may be used, but in all such cases the kind of bath shallbe stated.Duplicate determinations should agree within less than 1.0° C.Hence, if the variation is as much as 1.0° C.
A third test should bemade.V. TYPICAL DETERMINATIONSTo show the kind of agreement that can be expected with rings ofextreme variations of dimensions within the limits of the specifications,two straight and two beveled rings of the following dimensions wereselected:Straight ringsBeveled ringsIIIIIIIVInside diameter15.7621.036.45mm15.9321.056.23mmf U7.22 2 15.7821.016.46mm1 17.
40Outside diameter2 15. 9421.05Depth6.23Top. Bottom.Walker Test for Softening Point of Bituminous Materials, Etc. 201Using these rings the following results were obtained on threesamples of asphalt:Asphalt No.Ring No.BathInitialtempera-tureRise perminuteSoften-ing point1.i bi iii1 ni1 IV1 BfWater°C.55225°C.j 74.01 74.62LdoI 74.0f 49.
J 49 - 23.1Glycerine.-l 49.I 48.8f 91.05 J( 90.0The writer is indebted to G. Clarvoe, jr., for the drawing andsuggestions regarding the apparatus and to L. Kleinschmidt forthe typical determinations.Washington, August 30, 1929.
Full text of 'RP 142THE RING AND BALL METHOD OF TEST FOR SOFTENINGPOINT OF BITUMINOUS MATERIALS, RESINS, ANDSIMILAR SUBSTANCESBy Percy H. WalkerABSTRACTThe softening point of materials which, like asphalt, have no definite meltingpoint, but which when heated gradually change from brittle or very thick andslow-flowing materials to more mobile liquids, can only be determined by somearbitrary method. The ring and ball method which briefly consists of determin-ing the temperature at which a disk of the material held in a ring and loaded witha ball will flow through a definite distance when heated at a prescribed rate is oneof the best methods for such tests. Published directions for making the test are,however, open to very serious objections, and this paper describes the apparatusand procedure used at the National Bureau of Standards. The principal modi-fications in the apparatus are a beveled instead of a cylindrical ring, and acentering device for the ball. The procedure is so described that some latitude innonessential details is permitted.CONTENTSPageI. Introduction 195II.
Apparatus 1961. Container 1984. Thermometer 1995. Support for ring and thermometer 199III. Preparation of sample 199IV.
Procedure 1991. Bituminous materials, resins, etc., having softening points80° C. Or lower 2002.
Bituminous materials, resins, etc., having softening pointshigher than 80° C 200V. Typical determinations „. INTRODUCTIONThere are many materials which, like asphalt, have no definitemelting point, but which when heated gradually change from brittleor very thick and slow-flowing materials to softer or more mobileliquids.
For such materials the ring and ball method is a valuablemethod of test. Briefly, this test is a determination of the tempera-ture at which a disk of the material held in a ring and loaded with aball will flow through a definite distance when heated at a prescribedrate. However, it is an arbitrary method and in order to get agreeingresults a fixed, arbitrary, and closely defined method must be used.The method is best known to laboratories that test asphalt, andthe A. T.M.inl916 adopted a tentative description of the method,amended this and adopted it as standard in 1919, and has sincerevised it several times, the latest revision being in 1926 under serialdesignation D36-26. Standards, Pt. 496; 1927.195196 Bureau of Standards Journal of Research ivoi.4The A.'
Specifications for this test are open to the followingobjections:1. The apparatus as described is not used, nor can it be easily usedto meet the rigid requirements given in the text. For example, thering is supported on one side by a brass wire 1.83 mm in diameterwhich is supported in a cork held in a clamp, and this must be placedexactly 2.54 cm above the bottom of the beaker and 5.08 below thesurface of the water.2. Tolerances are given for inside diameter and thickness of thering, but not for its depth.3. The method is limited to asphalts, while if properly describedit can be used with numerous materials.4. The cylindrical ring specified limits its use to materials likeasphalt that do not shrink away from the ring.
A slightly beveledring gives with asphalts the same results as the cylindrical ring andhas the distinct advantage that it can be used with resins and pitcheswhich may shrink away from the cylindrical ring.5. Method prescribes unessential limitations in thekind and set-up of apparatus, while there is not reason why a numberof different forms of apparatus can not be used provided they allcomply with certain requirements.Hence, it seems desirable to describe the apparatus and method asused at the Bureau of Standards.II. APPARATUSThe essential apparatus is as follows:1. RINGA brass ring of the following dimensions:Depth.— 6.35 ±0.10 mm (ft inch).Inside diameter at bottom.
88 ±0.10 mm (% inch).Inside diameter at top. — Not less than inside diameter at bottomnor more than 17.6 mm, preferably 17.46 mm (% inch).Outside diameter at bottom.
— Not less than 18.0 mm nor more than21.0 mm.Outside diameter at top. — Not less than outside diameter at bottomnor more 21.0 mm.The interior of the ring may be either tapered, within the toler-ances given above, or cylindrical. (The tapered ring is to be preferred,as it can be used with all kinds of materials to which the ring and ballmethod is applicable. The cylindrical ring, while suitable for asphalts,can not be used with materials that shrink away from the ring, suchas resins and pitches.)The outside of the ring may be either uniformly cylindrical orsmaller at the bottom provided the above dimensions are compliedwith.
For convenience in mounting it is advisable to have it smallerat the bottom. BALLA steel ball, such as used in ball bearings, 9.53 mm (% inch) indiameter weighing between 3.45 and 3.55 g.walker Test for Softening Point of Bituminous Materials, Etc.
197198Bureau of Standards Journal of ResearchVol.!3. CONTAINERA glass vessel, capable of being heated, not less than 8.5 cm (3%inch) in diameter and not less than 10.5 cm (4% inches in depth fromthe bottom of the flare. (A 600 ml beaker, low form.)4.
THERMOMETERFor materials having softening points not above 100° C. A totalimmersion thermometer meeting the specification given in item 5331(d) of General Schedule of Supplies, Fiscal Year 1930, is used. 2For materials having softening points above 100° C. And below300° C.
A partial immersion thermometer meeting the specificationgiven in item 5331 (b) of the General Schedule of Supplies may beused. 3Diameter, 6.0 to 7.0 mm.Length, 20 to 30 mm. Diameter, not2 This specification is as follows:Type. — Etched stem, glass.Liquid. — Mercury.Range and subdivision. — Minus 4° to +104° C. In 0.2°.Total length.
— 454 to 460 mm.Stem. — Plain front, enamel back, suitable thermometer tubing.Bulb. — Corning normal or equally suitable thermometric glass.greater than stem.Distance to —4° line from bottom of bulb.— 50 to 70 mm.Distance to +104° line from top of thermometer. — 20 to 50 mm.Filling above mercury.
— Nitrogen gas.Top finish. — Glass ring.Graduation.— All lines, figures, and letters clear cut and distinct. Lines corresponding to even degreemarks to be longer than the remaining lines. Graduations to be numbered at each multiple of 2°.Immersion. — Total.Scale error. — The error at any point of the scale, when the thermometer is standardized at total immersion,shall not exceed 0.3°.Special marking.— A serial number and the manufacturer's name or trade-mark shall be etched on thestem.Case.
— The thermometer shall be supplied in a suitable case, on which shall appear '—4° to +104° C.in 0.2°, total immersion.' 3 This specification is as follows:Type. — Etched stem, glass.Liquid. — Mercury.Ranges and subdivisions. — Minus 5 to +300° C. In 1°.Total length.— 379 to 383 mm.Stem.
— Plain front, enamel back, suitable thermometer tubing. Diameter, 6 to 7 mm.Bulb. — Corning normal or equally suitable thermometric glass. Length, 10 to 15 mm. Diameter, 5 to6 mm.Distance to 0° line from bottom of bulb.— 90 to 100 mm.Distance to 300° line from top of stem. — 25 to 50 mm.Filling above mercury. — Nitrogen gas.Top finish.— Glass ring.Graduation.— All lines, figures, and letters clear cut and distinct.
The first and each succeeding 5° lineto be longer than the remaining lines. Graduations to be numbered at each multiple of 10°.Immersion. — The words ' 76 mm immersion ' and a line around the stem, 75 to 77 mm above the bottomof the bulb, shall be etched on the thermometer.Special marking. — A serial number and the manufacturer's name or trade-mark shall be etched on thestem.Scale error.— The error at any point of the scale, when the thermometer is standardized as providedbelow, shall not exceed 1°.Standardization.
— The thermometer shall be standardized for 76 mm immersion and for the followingtemperatures of the emergent mercury column. These stem temperatures have been chosen as correspond-ing, on the average, to those likely to occur in the use of the thermometer:Thermom-eter readingAveragetemperatureof emergentmercurycolumn961707680Case.— The thermometer shall be supplied in a suitable case on which shall appear the marking: '-5° to+300° C., 76 mm immersion.'
Partial-immersion thermometer for general use —5° to 300° C., D-183-25 meets thisspecification.walker Test for Softening Point of Bituminous Materials, Etc. Thermometer (seeA. D-36-26) gives within its range readings identical withthe -4° to + 104° C. Thermometer specified above.
P., +30° to 160° C. Thermometer (D-36-26) will read veryslightly higher than the —4° to +104° C. Total-immersion thermom-eter, the difference being less than 0.3° at 80° C.
And about 0.3° or0.4° at 100° C. The partial-immersion thermometer gives truetemperature readings which as compared with the total-immersionthermometer (used for partial immersion as in this test) will beabout 0.6° to 0.7° higher at 80° C.
And 1.0° to 1.1° higher at 100° C. SUPPORT FOR RING AND THERMOMETERAny convenient method for supporting the ring may be usedprovided it meets the following requirements: The ring must besupported in a substantially horizontal position; the top of the ringmust be at least 8 cm below the top of the container and the bottomof the ring 2.54 ±0.02 cm (1 inch) above a horizontal plate or thebottom of the container; the distance from the center of the ring tothermometer bulb must be not more than 16.5 mm.A device for centering the ball is desirable, but not essential.III. PREPARATION OF SAMPLEMelt the sample and stir it thoroughly, avoiding incorporatingair bubbles in the mass, and then pour it into the ring so as to leavean excess on cooling. The ring while being filled should rest on abrass plate that has been amalgamated to prevent the sample fromadhering to it. After cooling, cut off the excess material cleanlywith a slightly heated knife. Determine the softening point withinthree hours after the sample is prepared.IV. BITUMINOUS MATERIALS, RESINS, ETC., HAVING SOFTENINGPOINTS 80° C.
OR LOWERFill the glass container to a depth of not less than 9 cm with freshlyboiled distilled water that has been cooled to not less than 45° C.below the softening point of the material under test, provided suchsoftening point is not below 50° C. If the softening point is below50° C. The water shall be cooled to not above 5° C.
Place the filledring and ball, but not in contact, in the bath and maintain the initialtemperature for 15 minutes. Then place the ball in the center ofthe upper surface of the material in the ring, and at once suspendthe support carrying the ring, ball (ball guide if used), and horizontalplate so that the top of the ring is not less than 5.1 cm below thesurface of the water and the —4.0° to +104° C. Thermometer ishanging approximately in the middle of the container. The figureshows details of ring, ball guide, support, container, and assemblyof apparatus except tripod and burner. Apply heat in such a man-.
The use of a total-immersion thermometer for materials of low softening points and of partial-immersionthermometers for materials of higher softening points is recognized as a disadvantage; but the thermometersselected appear to be the best available in their respective ranges, and their use avoids the introductionof new and special thermometers for this work,200Bureau of Standards Journal of ResearchVol. 4ner that the temperature of the water after the first three minutesof heating is raised uniformly 5.0° ± 0.5° C. To facilitateuniform heating, it is advisable to place the burner midway betweenthe center and the edge of the beaker away from the specimen.Report as the softening point the temperature indicated by thethermometer (adding or subtracting any certified corrections, butmaking no emergent stem corrections) at the instant the sampletouches the horizontal plate or the bottom of the container.2. BITUMINOUS MATERIALS, RESINS, ETC., HAVING SOFTENINGPOINTS HIGHER THAN 80° C.Use the same method as given under IV, 1, except that instead ofwater a suitable bath shall be used, and with materials having softeningpoints above 100° C. The — 5° to 300° C.
Partial-immersion thermometershall be used. Glycerine is suitable for asphalts and unlessotherwise specified shall be used. When the nature of the materialtested indicates that glycerine is not suitable, other liquids, air, orinert gases may be used, but in all such cases the kind of bath shallbe stated.Duplicate determinations should agree within less than 1.0° C.Hence, if the variation is as much as 1.0° C.
A third test should bemade.V. TYPICAL DETERMINATIONSTo show the kind of agreement that can be expected with rings ofextreme variations of dimensions within the limits of the specifications,two straight and two beveled rings of the following dimensions wereselected:Straight ringsBeveled ringsIIIIIIIVInside diameter15.7621.036.45mm15.9321.056.23mmf U7.22 2 15.7821.016.46mm1 17.
40Outside diameter2 15. 9421.05Depth6.23Top.
Bottom.Walker Test for Softening Point of Bituminous Materials, Etc. 201Using these rings the following results were obtained on threesamples of asphalt:Asphalt No.Ring No.BathInitialtempera-tureRise perminuteSoften-ing point1.i bi iii1 ni1 IV1 BfWater°C.55225°C.j 74.01 74.62LdoI 74.0f 49. J 49 - 23.1Glycerine.-l 49.I 48.8f 91.05 J( 90.0The writer is indebted to G. Clarvoe, jr., for the drawing andsuggestions regarding the apparatus and to L. Kleinschmidt forthe typical determinations.Washington, August 30, 1929.