Sentence:  A contract of lease was entered into between the pursuer, who is the proprietor of the estate of Bargaddie, on the one part, and William M'Creath and others, carrying on business under the firm of the Bargaddie Coal Company, on the other part, ... and the lessees becoming bound to pay to the pursuer the sum of £500 sterling of fixed yearly rent, or, in his option, a lordship of 5½d. per cart of the gross output of coals, such cart weighing 13 cwt., and the coals being riddled through a riddle or <WSD>scree</WSD> of the customary size. 
Meaning of the word marked with <WSD> tags:  A coarse sieve.