It is said that while there was forbearance on the part of the teachers in this matter, there was no promise to forbear and therefore no real consideration for the promise of increased pay. But actual forbearance is evidence of an agreement to forbear, and in the absence of proof to the contrary is often held to be incompatible with any other condition. Waters v. White, 75 Conn. 88, 91, 52 A. 401; Breed v. Hillhouse, 7 Conn. 522, 527; Boyd v. Freize, 71 Mass. 552, 555. This latter is the situation here shown.