The ordinates of the curve give the strain in cwts., and the **abscissae** the distance in miles measured from the Canso end; as the strain is proportional to the depth, 18 cwts.

7 represents the specific volumes of mixtures of ammonium and potassium sulphates; the ordinates re presenting specific volumes, and the **abscissae** the per centage composition of the mixture.

9 illustrates the first case: the ordinates represent specific volumes, and the **abscissae** denote the composition of isomorphous mixtures of ammonium and potassium dihydrogen phosphates, which mutually take one another up to the extent of 20% to form homogeneous crystals.

During the first stage, when the magnetizing force is small, the magnetization (or the induction) increases rather slowly with increasing force; this is well shown by the nickel curve in the diagram, but the effect would be no less conspicuous in the iron curve if the **abscissae** were plotted to a larger scale.

The sides of the trapezette are the " bounding ordinates "; their **abscissae** being xo and xo+H, where H is the breadth of the trapezette.

Von Rohr's Theorie and Geschichte des photographischen Objectivs, the **abscissae** are focal lengths, and the ordinates wave-lengths; of the latter the Fraunhofer lines used are A' C D Green Hg.

The ordinates give the wave-lengths in, up. The **abscissae** give fc in 0.01 mm., commencing at fc fF.

The **abscissae** represent intervals of time, the ordinates the measured lengths of the growing filament.

The enclosed area for each temperature represents the total emission of energy for that temperature, the **abscissae** are the wavelengths, and the ordinates the corresponding intensities of emission for that wave-length.

The curve BPC is generally used with the **abscissae** spaced more conveniently for practical applications, and a modification of the diagram by J.