On the 18th July, 1855, they left Sydney for Moreton Bay, in the barque MONARCH, attended by the schooner TOM TOUGH. At Moreton Bay they took on board the remainder of the party, with fifty horses and two hundred sheep, and after some accidents caused by the MONARCH running on a reef, reached Point Pearce at the mouth of the Victoria River, on the 24th September. Here the horses were landed, much weakened by their voyage, and Gregory, Dr. Mueller, and seven men proceeded to the upper part of the Victoria overland, leaving the schooner to work her way up the river with the sheep on board. The land party first made the Macadam Range, so named by Stokes, thence they went to the Fitzmaurice River, where their horses were attacked by alligators and three of them severely wounded; and on the 10th of October they reached the Victoria, and rejoined the remainder of the party. Unfortunately, troubles had now set in, the schooner was aground on a bank eight miles below the camp, and having sprung a leak a considerable quantity of stores were damaged; the sheep, too, had been foolishly kept penned up on board, and so many had died that when finally landed the number was reduced to about forty. All this considerably weakened Gregory's resources. An attempt to ascend the river in an india-rubber boat was a failure, the craft not being adapted to surmount the obstacles encountered in the shape of rocky bars. On the 24th of November, Gregory, with his brother, Dr. Mueller, and Wilson, followed the Victoria to the south, on horseback. The party reached latitude 161 south, finding the tributary sources of the river to flow from fine open plains, and level forest country, all well grassed. From this point they returned to camp.