Venkataramana Rao, J.

1. This appeal raises a question of subrogation. The facts necessary for the disposal of the same lie in a narrow compass. The plaintiff sued to recover a sum of Rs. 8,000 on a mortgage dated 3rd October, 1925, executed by defendants 1 to 4 and their father late Subbarayudu in her favour. There was a prior mortgage on the said property dated 1st August, 1914. In execution of a decree obtained thereon the property mortgaged was about to be sold. To discharge the said decree debt the mortgagors - late Subbarayudu and his sons - agreed to sell a part of the said property, namely, plaint items 3 to 7, 9 and 15 to defendants 6 and 7. In pursuance of the said contract, the defendants 6 and 7 obtained a sale-deed dated 2nd November, 1933, and advanced the money with which the said decree debt was satisfied. They therefore claim a right of subrogation in respect of the said sum on the ground that by their having discharged the said decree debt they are subrogated to the rights of the mortgagee under the deed dated 1st August, 1914. The learned Subordinate Judge refused to give them the said relief on the ground that there is no registered instrument reserving t