=16.= The rules of the board of trade provide that on time contracts, purchasers shall have the right to require of sellers as security, a deposit of ten per cent, which amount is based on the contract price of the property purchased; they are also further allowed to demand security from time to time to the extent of any advance in the market value above selling price. Sellers shall have the same right on property sold, and, in addition, any difference that may exist or occur between the estimated legitimate value of any such property and the price of sale. It is required that all securities shall be deposited with the treasurer of the association or with some bank duly authorized by the board of directors to receive such deposits. The board requires in each instance a memorandum which shall state the name of the depository, the date on which the deposit is made, the name of the depositor, and also the name or names of the party or parties in whose favor the deposit is to be made, together with the amount of such deposit in detail and also in the aggregate. The left-hand part of the memorandum is retained by the depository selected, the right-hand portion thereof being taken by the depositor after being duly signed by the person authorized to receipt for the said deposit, and without delay this memorandum must be placed in the office of the clearing house. A detail of this memorandum is shown in Fig. 1. Upon the fulfillment or settlement of any contract or upon the closing of any contract—deposits upon which have been made—when the full adjustment of all differences relating to the same shall have been effected, the deposit shall be paid to the party depositing. COMMISSIONS ALLOWED BY BOARD TO BROKERS =17.= The commissions to be collected by brokers from customers are fully prescribed by the board of trade in each city and do not materially differ. While it will not be possible to give all the rates of brokerage or the charges allowed for buying, selling, or accounting, the commissions allowed on the Chicago Board of Trade for buying _or_ selling, or for buying _and_ selling, are as follows: For the purchase, or for the sale, or for the purchase and sale by grade alone of wheat, corn, or oats, to be delivered in store, either for immediate or for future delivery, one-eighth of one cent per bushel. For the purchase, or for the sale, or for the purchase and sale, by grade alone, of rye, barley, or flax-seed, to be delivered in store, either for immediate or for future delivery, one-quarter of one cent per bushel. For the purchase, or for the sale, or for the purchase and sale of lard, six cents per tierce. For the purchase, or for the sale, or for the purchase and sale of pork, five cents per barrel. For the purchase, or for the sale, or for the purchase and sale of D. S. short ribs, or D. S. extra short clears, twenty-five cents per thousand pounds.