Page 23, Mr. Horneman informs us, “_that the northern part of the building is erected on a native calcareous rock, rising about eight feet above the level of the area, within a circumvallation_,” which he particularly and exclusively describes, and which will be a subject of further dissertation. He then mentions, “that two vast stones of the roof have fallen in from the southern part of the building, and lay with their bottom nearly on a level with the plain of the outward enclosure;” and he was thence led to conjecture, that the base or floor of the southern division, was originally lower than that of the northern end. The difference in measurement or estimate of height stated by the two travellers, strongly corroborates the fact. It may be premised, that when an object is of no great altitude, an estimate of height may be made on mere inspection or view, with much more accuracy than any other line of dimension. A comparison with known objects, the stature of any human figure near, nay, the very person of the observer himself, will furnish a sort of scale for reference, by which he may compute from four to five times his own height with considerable precision. A difference so great as that of from eighteen to twenty-seven feet in estimating the altitude of the building at Siwah, could not occur between two the most hasty and inaccurate observers, in noting the height of the same object. The object itself, therefore, must be considered as different; and in the one case, to be that of the _wall within_, and in the other case, that of _the temple from without_. Mr. Brown taking his measurements in the clear, would ascertain the perpendicular of the wall from a part of the pediment or floor, the most clear and perfect; and this was, at the northern end. The dilapidations in the southern part of the building, do not appear to have attracted his notice in any other consideration, than as mere ruins: and merely as such, the unequal and broken surface would not be preferred for placing a rod in measurement to the summit, or from whence to look up and make a calculation of height. Mr. Brown accordingly measured the height from a proper base at the northern end, and found it to be eighteen feet. It has been already cited from the journal of Mr. Horneman, that the northern end was built on an isolated rock, rising eight feet above the plain of the general enclosure. The top of the wall from north to south, must have run on a level, and in a direct line: and the actual building of the southern part must have been eight feet higher than that of the northern end; and the entire building _from without_ must have appeared, and in truth, have been, twenty-six feet high, even to conform with Mr. Brown’s description from within. The two travellers in other points agree, as to the architecture of the building, and sculpture on the walls, concurring in proof, that it was of the highest antiquity, and of Egyptian origin.