227 deg. 0.395
232 deg. 0.355
236 deg. 0.310
240 deg. 0.267
245 deg. 0.226
250 deg. 0.183
255 deg. 0.140
261 deg. 0.097
266 deg. 0.060
271 deg. 0.023
290 deg. 0.000

[Footnote 1: _Vide_ Burgh, "Modern Marine Engineering," page 176 _et
seq._ M. Couste, _Annales des Mines_ V 69. _Recherches sur Vincrustation
des Chaudieres a vapour_. Mr. Hugh Lee Pattison, of Newcastle-on-Tyne,
at the meeting of the Institute of Mechanical Engineers of Great
Britain, in August, 1880, remarked on this subject that "The solubility
of sulphate of lime in water diminishes as the temperature rises. At
ordinary temperatures pure water dissolves about 150 grains of sulphate
of lime per gallon; but at a temperature of 250 deg. Fahr., at which the
pressure of steam is equal to about 2 atmospheres, only about 40 grains
per gallon are held in solution. At a pressure of 3 atmospheres, and
temperature of 302 deg. Fahr., it is practically insoluble. The point
of maximum solubility is about 95 deg. Fahr. The presence of magnesium
chloride, or of calcium chloride, in water, diminishes its power of
dissolving sulphate of lime, while the presence of sodium chloride
increases that power. As an instance of the latter fact, we find a
boiler works much cleaner which is fed alternately with fresh water and
with brackish water pumped from the Tyne when the tide is high than one
which is fed with fresh water constantly."]