forthwith. [1698-15, 27.] SECTION  300 . Filling of Vacancy by Appointment of Person or Persons in Lower Grade . — With the prior approval of the Governor-General or proper head of Department, a vacancy in a position of any grade may be filled by the appointment of one person or more  of a lower grade; but in such case the aggregate of salaries paid shall not be greater than the salary authorized by law for that position. [1698-18.] SECTION  301 . Bonds Required of Private Persons — Duties of Bureau Chief in Respect Thereto . — The chief of each Bureau shall, consistently with law, prescribe the form and fix the amount of all bonds executed by private parties to the Government under the  laws pertaining to his Bureau and shall pass on the sufficiency of the security and retain possession of the bond. SCHIac When it appears that any such bond is risky or insufficient, such chief may require better security, and after notice to the party concerned, and upon his failure within a reasonable time to give better security, or additional security, may abrogate the pr ivileges secured by the giving of the bond, but such action shall be without prejudice to the liability of any person or property already obligated. SECTION  302 . Contract for Transportation Equipment Belonging to Employee — Loan for Purchase of Equipment . — Subject to restriction and regulation by executive order the chiefs of Bureaus may, in the absence of other adequate transportation equipment, ente r into contracts with employees for the use by the latter, respectively, on official business, of transportation equipment owned by them, at a rental to be paid from the transportation-expense funds of the Bureau in question; but no allowance hereunder sha ll be in excess of twenty pesos per month in the case of a horse, or thirty pesos per month in the case of motor vehicles or vessels. When the nature of the official duties of any such employee justifies the permanent assignment to him of transportation eq uipment for his official use, he may, in the absence of other suitable means of transportation and with the prior approval of the proper head of Department, be loaned from the same funds an amount sufficient to purchase the necessary means of transportatio n, not to exceed four hundred pesos for an American horse or motor vehicle and two hundred pesos for a native horse, such loan to be repaid to the Government in monthly installments of not less than ten per centum of the amount loaned. ARTICLE  II Copyright 2012 CD Technologies Asia, Inc. and Accesslaw, Inc. Philippine Law Encyclopedia 2011 102