Any money disbursed by seller for any of the following reasons shall be an additional charge upon the property, and one-quarter of it shall be assumed by purchasers as additional money due seller over and above the amount already stipulated as payable by them on or before _________[date], and shall bear interest at the rate of _____% per annum, payable _________, from the date of such disbursements. (1) Seller is by this agreement authorized by purchasers to pay any amounts on account of the principal of the first mortgage mentioned above, either as installments of it become due or to procure releases of parts or parcels of the premises described in this agreement, and also to pay all interest due on it whenever the same becomes due and payable; (2) to pay all general taxes, special taxes and special assessments which become due on any later date; (3) to install and pay for, whenever it may be necessary or advisable, any improvements such as sidewalk, sewer, water mains, gas mains, and electric light service. Seller is also authorized by purchasers to at any time make any plat or plats of subdivision of any part or all of the above described premises; to sell by deed or contract, at any price that —he may see fit, any part or parcel of the premises: Provided, however, that purchasers are credited with one-quarter of the proceeds of any such sale, and to lease any part or parts of the above described premises at any rental that in h— judgment he may deem sufficient, provided purchasers are credited with one-quarter of it.