The Chinese, who begin their day at midnight, and reckon to the midnight following, divide this interval into twelve hours, each equal to two of ours, and distinguished by a name and particular figure. In Egypt the day was divided into unequal hours. The clock invented by Ctesibius, of Alexandria, 136 years B.C. was so contrived as to lengthen or shorten the hours. The Greeks divided the natural day into twelve hours--a practice derived from the Babylonians. The Romans called the time between the rising and setting sun, the natural day; and the time in the twenty-four hours, the civil day. They began and ended their civil day at midnight, and derived this practice from their ancient jurisprudence and rites of religion, established long before they had any idea of the division into hours. The first sun-dial seen at Rome was brought from Catania, in Sicily, in the first punic war, as part of the spoils of that city; and after this period, they divided the day into twenty-four hours. An officer, called _accendus_, used to proclaim the hours; and at the bench of justice (says Kennett) gave notice every three hours what it was o'clock. Throughout the Turkish empire, time is reckoned by certain portions of the natural day, resembling the vigils of the ancient Jews and Romans. Public clocks not being in use, these divisions of time are proclaimed from the minarets. P.T.W. * * * * * THE TOPOGRAPHER. TRAVELLING NOTES IN SOUTH WALES. _Voyage up the Bristol Channel_.--Two steam-packets ply twice every week throughout the year between Bristol and Swansea. The opposition has been so great this season, that the cabin fare is only 5_s_. and the steerage 2_s_. 6_d_. for a distance of seventy-five miles. The voyage down is performed in fine weather in about six hours; while, in consequence of the tide being adverse, it requires from nine to ten hours to make the voyage up the Channel. We hardly know any voyage so pleasant of the same length, for the scenery along the shores of the Severn sea, as it is well known, is singularly romantic and beautiful. We will give a rapid description of the voyage to Bristol:--Let us suppose ourselves darting between Swansea pier-heads, in the well-known _Palmerston_ steamer, with her opponent, the _Bristol_, in her wake. After crossing Swansea Bay, you pass Porthcawl, about fifteen miles from Swansea, where a harbour has been formed, at a great expense, by an extensive new coal company, whose works lie fourteen miles distant. This coast is exposed to all the fury of the Atlantic, the surf against the cliffs appearing very distinct at Swansea; and the task of forming the Breakwater must have been a difficult one. The steamers now keep close along shore, in a channel inside the Nass Sands--an extensive and dangerous bank to seaward. The contrast between the immense and tumultuous masses of breakers over these sands,