for the covenant on the part of Thompson that he would for two years publish no books except 'Texas History, Almanac, and the Tice Almanac,' and would devote his energies largely for two years to the vigorous prosecution of the sale of Hubbard's books exclusively, paying for the same within 60 days from date, all bills at the rate of 65 per cent. off from retail prices, and for all circulars, pros