Page:Philosophical Transactions - Volume 001.djvu/46

 Montauban, are for the River Agoust; those of Tholouse, for Riege; and the rest, for Lers.

Now concerning his Opinion upon this Proposition, he thinks, that all that hath been represented touching this matter, can signify very little seeing that the main thing is wanting, which is the assurance, and certain and positive mensuration of the height and quantity of the Waters, necessary to fall into both the Channels of the Aude and Garonne; that there must be plenty of that, to furnish at all times and alwaies the highest and first Sluces, since what once issues thence, doth never cuter again into them; and after some Boats are passed, if there should not be a sufficient supply for those that come after, either to go up, or to go down, all would stand dry, and Merchants and their Commodities would stay long enough expecting the supply of Rains, to their great detriment. He concludeth therefore, that no knowing and discreet Person is able, in matters of this nature, to give a positive answer, without having before him a large and exact Topographical Map of those places, and of the sources of all the Rivolets, that are to supply the Water to the Head of the pretended Channel, together with a full account of the survey and mensuration of all the places, through which it is to pass; of the Nature of the Ground, whether it be stony, sandy, rocky, &c. of the exact level of all the places, where it is to be made, and of the several risings and depressions thereof; to be assured that the Water may be conveyed to the greatest rising, and to the highest Sluce; and lastly, of the quantity, that may be had at high, middle, and low Water, to have enough for all times; that all these things being first made out, 'tis then time enough to judge of the possibility of the thing, and to calculate the Charges necessary for Execution.

This Artist having thus prudently waved this Proposition, diverts himself with reflecting upon several others of the like nature, among which he insists chiefly upon two, whereof one is that so much celebrated in Egypt,; the other, of Germany. And he is of Opinion, that the most important of all is that, of conjoining the Red sea by the Nile with the Mediterranean, which he looks upon as the most excellent convenience to go into the East-Indies without doubling the Cape of Good-Hope; and yet it Rh