A window shalt thou make to the ark, and in a cubit shalt thou finish it above; and the door of the ark shalt thou set in the side thereof; with lower, second, and third stories shalt thou make it.
A window shalt thou make to the ark. [Hebrew, tsohar (H6672)] - light; a collective noun, and therefore construed with the feminine, whence the next clause is rendered "of a cubit long shalt thou make them" - namely, the windows, formed of some transparent substance unknown. It is maintained by some, on the ground of Genesis 8:6, that there was only one window. But that passage is not conclusive on the point, and the great probability is that there were more windows in so large a structure. The Septuagint, instead of "window," translates the words, 'thou shalt make the ark in a gathering together upward.' Rosenmuller renders it 'roof,' and considers the second clause a direction to raise the roof in the middle, seemingly to form a gentle slope for letting the water run off. Assuming this latter interpretation to be the right one, and proceeding according to mathematical calculations made by various authors, a writer in the 'Edinburgh New Philosophical Journal' gives the following very intelligible description of the vessel: 'The ark of Noah was formed of a rectangular base, having sides springing up from its edges and inclining inward, until they met over its middle; the coverings at the ends forming each an angle of about fifty degrees with the base.
A vessel constructed in this form would be altogether unfit for carrying sail. But this was not the purpose of the ark. It was intended only for floating on the surface; and, bearing this in mind, let us inquire what advantages the form secured. It was obviously possessed of great strength. In the triangular form every beam, like those of an anchor roof, formed a brace, longitudinally directed to resist any tendency to change of form. The partitions dividing the rooms within, running not only across, but lengthwise also, as the large dimensions of the structure evidently admit and imply, and the internal horizontal floors supporting both these again, furnished numerous braces to strengthen every part of the fabric. But this was not the only advantage. Its outward form was that which is of all others the best adapted to elude the force of the waves in a stormy sea. The most ample experience has proved that an inclined plane, such as it presented on all sides to the waves, renders their stroke harmless, as is seen in the sloping dikes of Holland and Denmark; in our own piers and breakwaters, which are found liable to little injury from the heaviest sea, when they are made to meet them in an inclined form; and, above all, in the old ships of the British navy, built with the upper decks narrower than the lower, and consequently having inclined inwardly.
By the special form of the ark now pointed out, its contents are necessarily reduced to a little less than one-half of what the parallelopiped affords. According to Dr. Arbuthnot, the best authority on such questions, the burden, granting the form to have been a parallelopiped, amounted to about 81,000 tons. The triangular form will still leave a capacity of more than 35,000 tons, allowing Dr. Arbuthnot's estimate of the cubit-forming yet a vessel so large, in comparison with any that we are accustomed to build, that we can easily conceive, as a detail of particulars would show, it was sufficiently ample for the purpose for which it was intended.' Having deemed it necessary to investigate the stability of equilibrium of a floating body of the form assigned to the ark, this writer found the result to be quite satisfactory.
The rule given by Laplace for determining the stability of equilibrium of a floating body is, That the equilibrium will be stable in every direction, when the sum of the products of each element of the section of the floating body, at the level of the fluid, into the square of its distance from that horizontal axis, through the center of gravity of the section, in relation to which the sum of the products is a minimum-is greater than the product of the volume of the displaced fluid, into the height of the center of gravity of the floating body, above the center of gravity of the volume. Suppose a vessel of the form of the ark to be immersed, by the weight of its materials and lading, to the depth of 6 cubits, which is rather more than one-third of its whole tonnage, and that the weight is so uniformly distributed, that the center of gravity is the same as if the body were homogeneous, in that case the former sum would be to the latter in the proportion of 18 to 7 approximately. If the center of gravity were to continue the same, the ratio of the stability would decrease with a deeper lading, owing to the rapid decrease of the section of flotation. Were the body immersed to the depth of 9 cubits, which is very nearly one-half of its tonnage, the former sum would be to the latter only in the proportion of about 8 to 5; and were it immersed to the depth of 12 cubits, or somewhat less than two-thirds of its tonnage, the ratio of the former and latter sums would be only as 7 to 6. But it is, quite evident that in arranging the lading the center of gravity of the floating body may be brought below that of a homogeneous body, and that the facility of doing this increases with the depth of lading, insomuch that in very deep ladings the center of gravity of the floating body may be very easily brought below that of the displaced fluid, in which case the stability would be absolute in every rate of lading.'
Thus, the "fashion" or form of the ark was completely adapted for its purpose. God was pleased to employ human agency and ordinary means for the preservation of Noah and his family, and the living creatures that were saved with them; and if it be delightful to the contemplative mind to observe the numberless wise contrivances, the uses and ends displayed, the infinity of wisdom, in short, poured over the immensity of his creation, it is also highly gratifying to find an analogous proof of wisdom in its admirable adaptation to its end, in this structure, fabricated by his express direction.'