A bond of indemnity should receive a reasonable construction in order to carry out the in-tención pi' the parties as expressed by the language used. Such bond camiot be held to inure to the benefit of one not a party thereto nor designated therein unless it clearly appears from its terms that it was intended that .■•ucii party should be the beneficiary thereof, or the terms employed therein are ambiguous and susceptible of two interpretations which seem oij'jaily fair, in which event that interpretation should be adopted which affords the greater indemnity.