IMPROVEMENT, estates. This term is of doubtful meaning It would seem to apply principally to buildings, though generally it extends to amelioration of every description of property, whether real or personal; it is generally explained by other words.

2. Where, by the terms of a lease, the covenant was to 1eave at the end of the term a water-mill with all the fixtures, fastenings, and improvements, during the demise fixed, fastened, or set up on or upon the premises, in good plight and condition, it was held to include a pair of new millstones set up by the lessee during the term, although the custom of the country in general authorized the tenant to remove them. 9 Bing. 24; 3 Sim. 450; 2 Ves. & Bea. 349. Vide 3 Yeates, 71; Addis. R. 335; 4 Binn. R. 418; 5 Binn. R. 77; 5 S. & R. 266; 1 Binn. R. 495; 1 John. Ch. R. 450; 15 Pick. R. 471. Vide Profits. 2 Man. & Gra. 729, 757; S. C. 40 Eng. C. L. R. 598, 612.

3. Tenants in common are not bound to pay for permanent improvements, made on the common property, by one of the tenants in common without their consent. 2 Bouv. Inst. n. 1881.


IMPROVEMENT, rights. An addition of some useful thing to a machine, manufacture or composition of matter.

2. The patent law of July 4, 1836, authorizes the granting of a patent for any new and useful improvement on any art, machine manufacture or composition of matter. Sect. 6. It is often very difficult to say what is a new and useful improvement, the cases often approach very near to each other. In the present improved state of machinery, it is almost impracticable not to employ the same elements of motion, and in some particulars, the same manner of operation, to produce any new effect. 1 Gallis. 478; 2 Gallis. 51. See 4 B. & Ald. 540; 2 Kent, Com. 370.