it is great to see someone actually checking the references the description in the article is my personal editorial freehand description of the equation on page no reference indeed i did not try to use clausius' terminology my aim was to present his idea in present day language if you feel like improving on it i will not be offended i referred to the paper to in order to defer to clausius' priority in stating the law i would still prefer to quote the paper rather than the one i have not tried to present the nearly simultaneous version by rankine but i would not object to seeing that done as well though i think it perhaps unnecessary