Our latest files are to April 21st, inclusive. Sydney was at that time in high spirits over the recent visit of the Prince Captain of H. M. S. Gallatea. The most noteworthy action of whom was the laying of the corner-stone of the testimonial to the hardy navigator and discoverer, Captain Cook. We extract the remarks of the leading journal of Sydney.

“The Captain Cook Memorial.—A monument to the memory of Captain Cook will be rather an expression of our admiration for his character and services than an enhancement of his fame. The last generation was filled with wonder at the narrative of his discoveries. The first quartos that record them display in most striking forms the scenes and objects he made known to the world. He visited many islands of the Southern seas, whose voluptuous and animated social life attracted as to a new-found Paradise. Subsequent experience scattered the illusions of fancy, but brought out more clearly the value of his labors. New South Wales presented to his view a land of savages, lowest in the scale of civilization, but it also offered a noble field for British colonization, perhaps less appreciated while America was still a dependency of England, but brought into notice a few years after that country ceased to belong to the Crown.

“Cook first landed at Botany Bay, on the 19th of April, and on the 23d of August, he took possession of the entire country in the name of the Sovereign of England. The precise spot where he anchored is marked in the charts by a nautical symbol, and can thus be identified. On reaching the shore he found a spring of water ample for the wants of the ship, and tradition has reported that he bent his knees in adoration of the Supreme Being.

“The character of Cook as a navigator occupies the first rank in nautical sciences. It is to his high honor, that modern times, though they have added to his discoveries, have been rarely able to dispute them. Nothing is superfluous—nothing is obscure. The modern investigator starts from the observations made by Cook as undoubted facts. Every year displays more strikingly, not only the results of his discoveries and their value, but the almost prophetic foresight which presided over them.

“The history of Captain Cook is an example of the lofty position which may be taken by the humblest ranks when attended with high intelligence and superior moral qualities. The first step of his naval career was as a cabin boy. He rose to the command of an expedition which was suggested by scientific men, and their warmest hopes were more than fulfilled. They had seen with regret the blanks in the map of the world, and the ignorance which prevailed in reference to the true character and capabilities of countries partially known. The men of science who accompanied him on his voyage acquired for a time a scarcely inferior fame. Mr. Banks and Dr. Solander are names familiar to the readers of Cook’s Voyages, but the magnificence of his achievements leaves in the shade every inferior merit. He stands forth as the founder of a new era in nautical discovery, and as the revealer of a new world.

“Could Captain Cook have seen the spot on which it is proposed to erect his monument, and from thence, with superhuman knowledge, anticipated the events of this day, he would have been overwhelmed with awe.

“Edmund Burke delineated, while the struggle with America was still transpiring, the emotions of astonishment with which he supposes Lord Bathurst, then an aged statesman, might in the days of his youth have looked forward, under the guidance of some celestial instructor, to the events which had raised American colonization from insignificance to greatness. But what emotions would have stirred the heart of Cook, if, standing on this spot, he had foreseen the progress of colonization, the painful labors included in the first fifty years, and the immense prosperity of the last.

“Had such heavenly anointing enabled him to foresee all this, his grateful spirit would have been filled—with—what sacred joy! Still further extending his intellectual prospect, he might have foreseen the arrival of a vessel furnished with the results of science then unattained, advancing like some being, instinct with intelligence, from port to port, through billows over which he was tossed, and independent of winds for which he had to wait, arrived at a fixed hour at the haven of its destination. And still farther, he might have seen the great grandson of that monarch whose name he proclaimed as the lord of this territory—the son of a royal woman who has inherited all the virtues of her race, without its faults; and he might have seen that son, surrounded with a multitude of her subjects, standing over the first stone of an edifice to do honor to his memory.”—Sydney Morning Herald, March 27.

“The New Post Office, Sydney.—The keystone of the central arch of the new Post Office, George street, was laid by His Royal Highness the Duke of Edinburgh, on the 1st instant, in the presence of a vast concourse of spectators. A large platform was erected behind the arch, and on a level with the stone, access to which was obtained by carpeted stairs, springing from the northern side of the building.

“The stone laid by the Prince forms the keystone, archivolts and two spandrils of the central archway of the George street front. Upon the face are to be carved the Royal arms, and upon the coffered soffits the arms of the Duke. The dimensions of the stone are:—Length 13 feet 6 inches, width 4 feet 6 inches, and height 6 feet 6 inches—the whole being equal to 394 cubic feet. The weight is twenty-six tons. This stone is doubtless the largest yet laid by his Royal Highness, and it is probably the largest block of sandstone he will ever lay, for it would be difficult, if not indeed impossible, to get sound blocks of sandstone of equal size from any quarry in England, or elsewhere. Few cities are so favorably situated for sandstone as Sydney, for in almost every direction blocks of this description of freestone may be obtained of almost unlimited dimensions, and without a flaw. The most casual observer of the new Post Office cannot fail to notice the massiveness of the stones used in the building, and the solidity of the structure is unequalled by any other erection in the city. The contractor has placed very powerful cranes in his quarries at Pyrmont, whence these immense blocks of stone are obtained, and great credit is due to Mr. C. Saunders for the workmanlike manner in which these blocks—far exceeding in size anything previously attempted in the colony—have been quarried. The difficulty of removing these heavy blocks of stone must be very considerable; and the stone laid by the Duke of Edinburgh was equal to the force of twenty-one horses, calculating a horse to draw about twenty-five cwt. Ordinary wagons or trucks usually carry weight not exceeding 5, or, at most, 6 tons; and as there are in this building many blocks of granite and freestone of 10 to 20 tons, the difficulty of carriage can easily be seen. In hoisting and fixing these large stones ‘travellers’ are used, which can move longitudinally and crossways; and as the lift is directly over the stone to be fixed, there is less liability of accident than by the use of cranes or other contrivances.