In addition to the above rules, there are many presumptions of law relating to agree ments, such as, that the parties to a simple contract intend to bind their personal repre sentatives ; that where several parties con tract without words of • severalty, they are presumed to bind themselves jointly; that every grant carries with it whatever is nec essary to its enjoyment; when no time is I mentioned, a reasonable time is meant ; and other presumptions arising out of the nature of the case.
It is the duty of the court to interpret all written instruments; see Middlesex Turnpike Corporation v. Swan, .10 Mass. 384, 6 Am. Dec. 139; Levy v. Gadsky, 3 Cra. (U. S.) 180, 2 L. Ed. 404; Hassett v. McArdle, 7 Misc. 710, 28 N. Y. SuPP. 48; Fidelity Title & Trust Co. v. Gas Co., 150 Pa. 8, 24 Atl. 339 ; written evidence; McCoy v. Light ner, 2 Watts (Pa.) 347; and foreign laws ; Duffle v. Black, 1 Pa. 388; and where the terms of a parol agreement are shown with out any conflict of evidence; Brannock v. Elmore, 114 Mo. 55, 21 S. W. 451; Elliott v.
Wanamaker, 155 Pa. 67, 25 Atl. 826; or where a contract is contained in letters, no matter how voluminous they may be ; Cin cinnati Punch & Shear Co. v. Thompson, 80 Kan. 467, 102 Pac. 848.
Whether a written contract, to be per formed in case a consolidation was effected between two corporations, is limited to one resulting from then pending negotiations, or whether it referred to a consolidation un der a renewal of negotiations a year later, extrinsic evidence of the circumstances and the acts and declarations of the parties is admissible, and where that is conflicting, the construction of the contract is for the jury; Donner v. Alford, 136 Fed. 750, 69 C. C. A. 402.
Contracts are to be construed liberally in favor of the public, when the subject-mat ter concerns the interests of the public; Joy v. St. Louis, 138 U. S. 1, 11 Sup. Ct. 243, 34 L. Ed. 843.
See CONSTRUCTION ; IN MITIORI SENSU ; RE CITAL ; TITLE ; NONSENSE ; ET CETERA ; FROM ; PREAMBLE; Beal, Cardinal Rules of Interpre tation; Black, Interpretation.