The foregoing has been introduced at the risk of confusing the lay reader, on the idea that all the various calculations regarding the drawing of "demand" against the remitting of long bills are founded on the same general principle, and that where it is desired to go more deeply into the matter the correct conditions can be substituted. Discount, of course, varies from day to day, "payment" bills do not go through the discount market at all, but are "rebated," the commissions charged different bankers and by different bankers vary widely. Under the circumstances the value of presenting a lot of hard-and-fast calculations worked out under any given set of conditions is extremely doubtful. As to the profit on business of this kind it can be said that the average, where the best bills are used, runs not much over twenty points (one-fifth of a cent per pound sterling). From that, of course, profits actually made run up as high as one cent or even two cents per pound, according to the amount of risk involved. The buying of cheap bills is, however, a most precarious operation. One single mistake, and the whole profit of months may be completely wiped out. The proposition is a good deal like lending money on insecure collateral, or like lending to doubtful firms. There are banking houses which do it, have been doing it for years, and by reason of an intuitive feeling when there is trouble ahead have been able to avoid heavy losses. Such business, however, can hardly be called high-class banking practice. 4. _The Operation of Making Foreign Loans_ In its influence upon the other markets, there is perhaps no more important phase of foreign exchange than the making of foreign loans in the American market. How great is the amount of foreign capital continually loaned out in this country has been several times suggested in previous pages. The mechanics of these foreign loaning operations, the way in which the money is transferred to this side, etc., will now be taken up.