SPECIFIC See also:

• HEAT (0. E. haktu, which like " hot," Old Eng. hat, is from the Teutonic type haita, hit, to be hot; cf. Ger. hitze, heiss; Dutch, hitte, heet, &c.)

HEAT OF See also:

• MERCURY
• MERCURY (MERCU1uus)
• MERCURY (symbol Hg, atomic weight = 2oo)

MERCURY BY CONTINUOUS ELECTRIC  METHOD Flow of Hg . Rise of Temp . See also:

• WATTS, ALARIC ALEXANDER (1797-1864)
• WATTS, GEORGE FREDERICK (1817-1904)
• WATTS, ISAAC (1674-1748)

Watts . See also:

• HEAT (0. E. haktu, which like " hot," Old Eng. hat, is from the Teutonic type haita, hit, to be hot; cf. Ger. hitze, heiss; Dutch, hitte, heet, &c.)

Heat-loss . Specific Heat . gm./sec. do EC MO Per gm. deg . 8.753 11.764 14.862 0.655 .13780 joules 4'594 12.301 7.912 0.685 .03297 cals . It is assumed as a first approximation that the heat-loss is proportional to the rise of temperature do, provided that do is nearly the same in both cases, and that the See also:

• DISTRIBUTION (Lat. distribuere, to deal out)

distribution of temperature in the apparatus is the same for the same rise of temperature whatever the flow of liquid: The result calculated on these assumptions is given in the last See also:

• COLUMN (Lat. columna)

column in joules, and also in calories of 2o° C . The heat-loss in this example is large, nearly 4'5 % of the See also:

• TOTAL

total See also:

• SUPPLY (through Fr. from Lat. supplere, to fill up)

supply, owing to the small flow and the large rise of temperature, but this correction was greatly reduced in.subsequent observations on the specific heat of See also:

• WATER

water by the same method . In the See also:

• CASE
• CASE, JOHN (d. 1600)

case of See also:

• MERCURY
• MERCURY (MERCU1uus)
• MERCURY (symbol Hg, atomic weight = 2oo)

mercury the liquid itself can be utilized to conduct the electric current . In the case of water or other liquids it is necessary to employ a See also:

• PLATINUM [symbol Pt, atomic weight 145.0 (0=16)]

platinum See also:

• WIRE (A.S. wir, a wire; cf. Swed. vire, to twist, M.H.G. wiere, a gold ornament, Lat. viriae, armlets, ultimately from the root wi, to twist, bind)

wire stretched along the See also:

• TUBE (Lat. tuba)

tube as See also:

• HEATING

heating conductor . This introduces additional difficulties of construction, but does not otherwise affect II s= 1 +0.0O0O4t+0.0000009t2 (See also:

• REGNAULT, HENRI (1843-1871)
• REGNAULT, HENRI VICTOR (1810-1878)
• REGNAULT, JEAN BAPTISTE (1754-1829)

Regnault), (3) for the specific heat s at any temperature t C. in terms of the specific heat at 0° C. taken as the See also:

• STANDARD
• STANDARD, BATTLE OF THE

standard .

This See also:

• FORMULA
• FORMULA (Lat. diminutive of forma, shape, pattern, &c., especially used of rules of judicial procedure)

formula has since been very generally applied over the whole range 0° to we C., but the experiments could not in reality give any See also:

• INFORMATION (from Lat. informare, to give shape or form to, to represent, describe)

information with regard to the specific heat at temperatures below too° C . The linear formula proposed by J . Bosscha from an See also:

• INDEPENDENT

independent reduction of Regnault's experiments is probably within the limits of accuracy between too° and 200 C., so far as the mean See also:

• RATE

rate of variation is concerned, but the See also:

• ABSOLUTE (Lat. absolvere, to loose, set free)

absolute values require reduction . It may be written- S =Sloo +.00023 (t-100) (Bosscha-Regnault) (4) . Me he See also:

• WORK

work of L . Pfaundler and H . Platter, of G . A . Hirn, of J . C . Jamin and Amaury, and of many other experimentalists who succeeded Regnault, appeared to indicate much larger rates of increase than he had found, but there can be little doubt that the discrepancies of their results, which often exceeded 5%, were due to lack of appreciation of the difficulties of calorimetric measurements . The work of See also:

• ROWLAND, HENRY AUGUSTUS (1848-1901)

Rowland by the See also:

• MECHANICAL

mechanical method was the first in which due See also:

• ATTENTION (from Lat. ad-tendo, await, expect; the condition of being " stretched " or " tense ")

attention was paid to the See also:

• THERMOMETRY (Gr. Bepµos, warm; µerpov, a measure)

thermometry and to the reduction of the results to the absolute See also:

• SCALE
• SCALE (1) A

scale of temperature .

The agreement of his corrected results with those of Griffiths by a very different method, See also:

• LEFT

left very little doubt with regard to the rate of diminution of the specific heat of water at 20° C . The work of A . See also:

• BARTOLI, DANIELLO (16o8-1685)

Bartoli and E . Stracciati by the method of mixture between 0° and 3o° C., though their See also:

• CURVE (Lat. curvus, bent)

curve is otherwise similar to Rowland's, had appeared to indicate a minimum at 2o° C., followed by a rapid rise . This lowering of the minimum was probably due to some See also:

• CONSTANT, BENJAMIN (1845-1902)

constant errors inherent in their method of experiment . The more See also:

• RECENT

recent work of Ludin, 1895, under the direction of Prof . J . Pernet, extended from 0° to too° C., and appears to have attained as high a degree of excellence as it is possible to reach by the employment of mercury thermometers in See also:

• CONJUNCTION (from Lat. conjungere, to join together)

conjunction with the method of mixture . His results, exhibited in fig . 6, show a minimum at 25° C., and a maximum at 87° C., the values being .9935 and 1.007 respectively in terms of the mean specific heat between o and too C . He paid See also:

• GREAT

great attention to the thermometry, and the discrepancies of individual measurements at any one point nowhere exceed 0.3 %, but he did not vary the conditions of the experiments materially, and it does not appear that the well-known constant errors of the method could have been completely eliminated by the devices which he adopted . The rapid rise from 25° to 750 may be due to See also:

• RADIATION, THEORY OF

radiation See also:

• ERROR (Lat. error, from errare, to wander, to err)

error from the hot water supply, and the subsequent fall of the curve to the inevitable loss of heat by evaporation of the boiling water on its way to the calorimeter .

It must be observed, however, that there is another See also:

• GRAVE

grave difficulty in the accurate determination of the specific heat of water near too° C. by this method, namely, that the quantity actually observed is not the specific heat at the higher temperature t, but the mean specific heat over the range 18° to t . The specific heat itself can be deduced only by differentiating the curve of observation, which greatly increases the uncertainty . The See also:

• PECULIAR

peculiar See also:

• ADVANTAGE

advantage of the electric method of Callendar and See also:

• BARNES, ALBERT (1798–1870)
• BARNES, BARNABE (1569 ?–16o9)
• BARNES, JOSHUA (1654-1712)
• BARNES, ROBERT (1495-1540)
• BARNES, SIR EDWARD (1776-1838)
• BARNES, THOMAS (1785-1841)
• BARNES, W
• BARNES, WILLIAM (1800-1886)

Barnes, already referred to, is that the specific heat itself is determined over a range of 8° to to° at each point, by adding accurately measured quantities of heat to the water at the desired temperature in an isothermal enclosure, under perfectly steady conditions, without any possibility of evaporation or loss of heat in transference . These experiments, which have been extended by Barnes over the whole range o° to too°, agree very well with Rowland and Griffiths in the rate of variation at 20° C., but show a rather See also:

• FLAT (a modification of O. Eng. flet, an obsolete word of Teutonic origin, meaning the ground beneath the feet)

flat minimum of specificheat in the neighbourhood of 38° to 40° C . At higher points the rate of variation is very similar to that of Regnault's curve, but taking the specific heat at 20° as the standard of reference, the actual values are nearly 0.56% less than Regnault's . It appears probable that his values for higher temperatures may be adopted• with this reduction, which is further confirmed by the results of See also:

• REYNOLDS, JOHN FULTON (182o-1863)
• REYNOLDS, SIR JOSHUA (1723-1792)
• REYNOLDS, WALTER (d. 1327)

Reynolds and Moorby, and by those of Ludin . According to the electric method, the whole range of variation of the specific heat between to° and 80° is only 0.5 % . Comparatively See also:

• SIMPLE

simple formulae, therefore, suffice for its expression to 1 in 10,000, which is beyond the limits of accuracy of the observations . It is more convenient in practice to use a few simple formulae, than to See also:

• ATTEMPT (Lat. adtemptare, attentare, to try)

attempt to represent the whole range by a single complicated expression:- Below 20° C. s=0.9982+0.000,0045 (t-4o)2-o.000,0005 (t-20)3 . From 20° to 6o°, s- 0.9982+0•000,0045 (t-40)2 (5) . ((s=0 9944 I 000 o4t~ o•000,000y tz (Regnault Above 6o° to 2000 j corrd.) (( s= 1.000+0.000,22 (t-6o), (Bosscha corrd.) The addition of the cubic See also:

• TERM

term below 2o° is intended to represent the somewhat more rapid See also:

• CHANGE (derived through the Fr. from the Late Lat. cambium, cambiare, to barter; the ultimate derivation is probably from the root which appears in the Gr. «a urmu', to bend)

change near the freezing-point . This effect is probably due, as suggested by Rowland, to the presence of a certain proportion of See also:

• ICE (a word common to Teutonic languages; cf. Ger. Eis)

ice molecules in the liquid, which is also no doubt the cause of the anomalous expansion .

Above 6o° C . Regnault's formula is adopted, the absolute values being simply diminished by a constant quantity 0.0056 to allow for the probable errors of his thermometry . Above too° C., and for approximate work generally, the simpler formula of Bosscha, similarly corrected, is probably adequate . The following table of values, calculated from these formulae, is taken from the Brit . Assoc .