A remarkable range consisting chiefly of trap-rock traverses the whole country between the Wollondilly and the sea in a south-east direction extending from Bullio to Kiama. The highest part is known as the Mittagong range and, in laying down the new line of road, it was an object of importance to avoid this range. Bowral, the highest part, consists of quartz or very hard sandstone. SANDSTONE COUNTRY. On leaving Berrima the road traverses several low ridges of trap-rock and then turns to the south-east in order to avoid the ravines of the Nattai; for we again find here that ferruginous sandstone which desolates so large a portion of New South Wales and, to all appearance, New Holland, presenting in the interior desert plains of red sand, and on the eastern side of the dividing range, a world of stone quarries and sterility. It is only where trap or granite or limestone occur that the soil is worth possessing, and to this extent every settler is under the necessity of becoming a geologist; he must also be a geographer, that he may find water and not lose himself in the bush; and it must indeed be admitted that the intelligence of the native youth in all such matters is little inferior to that of the aborigines. The barren sandstone country is separated from the seashore by a lofty range of trap-rock connected with that of Mittagong, and we accordingly find an earthly paradise between that range and the seashore. The Illawarra is a region in which the rich soil is buried under matted creepers, tree-ferns and the luxuriant shade of a tropical vegetation nourished both by streams from the lofty range and the moist breezes of the sea. There a promising and extensive field for man's industry lies still uncultivated, but when the roads now partially in progress shall have connected it with the rest of the colony it must become one of the most certain sources of agricultural produce in New South Wales. THE ILLAWARRA. The sandstone on the interior side extends to the summit of the trap range and its numerous ravines occasion the difficulties which have hitherto excluded wheel-carriages from access to the Illawarra. LUPTON'S INN. To cross a country so excavated is impossible except in certain directions, but the best lines these fastnesses admit of have been ascertained and marked out in connection with that for the great southern road, which ought to leave the present line at Lupton's Inn. I consider this the most important public work still necessary to complete the system of great roads planned by me in New South Wales; but I have not had means at my disposal hitherto for carrying into effect this portion of the general plan. From Lupton's Inn Sydney bore north-east, yet I was obliged to turn with the present road towards the north-west and to travel eleven miles over unfavourable ground in a direction to the westward of north.