The board of trustees is required to take from the banks such security in public bonds, or other securities, authorized by act of Con gress or supported by the taxing power, as the board may prescribe, approve and deem suf ficient and necessary to insure thc safety and prompt payment of such deposits on demand. If at any time the postal savings deposits in any State or Territory exceed the amount which the qualified banks therein arc willing to re ceive under the terms of the act, and such ex cess amount is not required to make up the re serve fund of .5 per cent, the board of trus tees is authorized to invest all or any part of the excess in bonds or other securities of the United States. When, in the judgment of the President, the general welfare and interest of the United States so require, the board of trustees is authorized to invest all or any part of the postal savings funds, except the reserve fund of 5 per cent, in bonds or other sccuri ties of the 'United States. The board of trus tees is authorized to purchase from the holders thereof bonds which have been issued to postal savings depositors in exchange for their de posits. The board of trustees is authorized at
any time to dispose of bonds held as postal savings investments and use the proceeds to meet withdrawals by depositors.
Interest and profit accruing from the de posit or investment of postal savings funds is required to be applied to the payment of inter est due to postal savings depositors, and the excess thereof, if any, is required to be covered into the Treasury of the United States as a part of the postal revenues.
Statistics for United States System.— The postal savings banks were opened in the United States on 3 Jan. 1911, at 48 second-class post offices, one in each State of the Union. Fol lowing is a statement shol,ving the growth of the system and giving a summary of its transactions at the end of each six months' period: Statistics for Foreign Countries.— Follow ing is a statement giving the principal numerical facts in connection with postal savings bank systems of countries other than the United States, as shown by Statistical Abstract of the United States for 1916, based on the official reports of the respective countries.