A cash book of Y Glog (Glogue) estate, Clydau, co. Pembroke, relating mainly to the slate-quarrying business of John Owen the younger (d. 1886), and recording payments from customers, mainly in co. Pembroke, and disbursements, 1867-1873 (ff. 1v-133), together with estate cash accounts and statement of rents, 1886-1891 (ff. 137-54).