The general characteristics of real-estate mortgages may be summarized as follows: (1) When carefully selected and purchased under favorable conditions, great safety of principal and interest; (2) a relatively high return; (3) a low degree of convertibility; (4) no prospect of appreciation in value; and (5) the practical certainty of maintaining the integrity of the principal invested. Is a security possessing these characteristics a suitable investment for a business surplus? Only to a limited extent. The safety, high return, and assurance against loss in quoted value of principal are all highly desirable qualities for this purpose, but the lack of convertibility is a fatal defect. No consideration is of greater importance in the investment of a business surplus than a high degree of convertibility, so that if the need should arise the investment may be instantly liquidated. The fact that real-estate mortgages can not be readily disposed of makes it practically impossible to employ them for the investment of a business surplus. Where convertibility is not an essential requirement, and where the want of promise of appreciation in value is not a serious matter, mortgages afford a very desirable form of investment. The characteristics which they possess in an eminent degree--safety, high return, and assurance against loss in quoted value of principal--are exactly suited to the ordinary requirements of savings-banks. Generally speaking, only a small proportion of a savings-bank's assets need be kept in liquid form or readily convertible, and accordingly they find mortgages highly desirable. For the purpose of private investment the attractiveness of mortgages is not so easy to determine. Ordinarily, fluctations in quoted values are of no great importance to the private investor, so that the absence of quotation which mortgages enjoy is not especially valuable. Their safety and high return are attractive qualities, but their want of convertibility and of prospect of appreciation in value are drawbacks. On the whole, the private investor may probably employ with advantage a certain part, but not too much of his estate in mortgage investments. As part of a scientific and comprehensive scheme of investment, the special advantages of real-estate mortgages appear most prominently in the years following a business depression. During such a period real-estate values are usually relatively low, but beginning to advance, so that mortgages present their maximum margin of security. At such a time they compare most favorably with bonds and other investment securities which are subject to changing quotations, because such securities are then apt to be at their highest point under the combined influence of restored confidence and the low money rates which usually prevail. After several years of continued and increasing business prosperity the positions are just reversed.