Allow current 2.

miles per hour.

Mean rate.

xxxviii APPENDIX.

in the course of a week ; and as it cannot be reckoned at less than one thousand three hundred Roman miles (supposing it to have been a coasting voyage), or at less than one thousand two hundred and twenty-five M.P., in straight course to the southward of Sardinia, we must conclude that the vessel in which it was performed actually sailed at the rate of more than one hundred and eighty-five M.P. in the first instance, and one hundred and seventy -five in the latter.

Other examples follow, of the coasting voyage just mentioned in detail — viz. from Ostia to the Provincia Narbonensis (say, the southeast point of the Gulf of Lyons), the Gallicus Sinus of the Romans, a distance of four hundred and fifty M.P., performed in the space of three days ; this gives a rate of one hundred and fifty miles per day.

From Ostia to the coast of Spain (Hispania Citerior), say the south-western point of the same Gulf, which is the nearest that can be taken, is four days ; this would give a rate of more than one hundred and sixty M.P. per day.

Again, from the same port (Ostia) to the coast of Africa, in two days ; which, taken at the nearest points, Carthage, or Utica, on the extremity of the .Hermseum Promontorium, could not be less than three hundred and fifty Roman miles in straight course. This will afibrd us a rate of one hundred and seventy-five M.P. per day, the exact rate of the sailing from Ostia to Gibraltar, in the straight course imagined above.

It does not appear that there is any mistake in the numbers here mentioned by Pliny ; for the instances are all of them consistent with each other ; one only being a little below one hundred and forty M.P. per day, and another one hundred and forty-three ; two examples afford one hundred and fifty, one hundred and sixty, two one hundred and seventy -five, and one one hundred and eighty-five. The lowest of these rates of sailing may be reckoned at between six and seven M.P. per hour, and the highest at something less than eight; giving a mean of seven M.P. per hour, which would be reckoned a good one for ships of the present day.

One of the reasons to which this great improvement in ancient