Dr. Thevenin mentioned several facts of much interest in their bearing on this question. In the first place, phthisis is all but completely unknown among the inhabitants of this part of Africa; while in Algeria cases are not rare among the natives, and in Egypt they are rather frequent. In the course of ten years he had met but five cases among his very numerous native patients, and in three of these the disease had been contracted at a distance. He further mentioned several cases among Europeans who had arrived in an advanced stage of the disease, on whom the influence of the climate had exercised a remarkable curative effect.
An examination of the tables, showing the results of M. Beaumier’s observations, and especially those for temperature, may help to explain these facts, as they certainly show that Mogador enjoys a more equable climate than any place within the temperate zone as to which we possess accurate information.
It should be mentioned that these observations were made with good instruments, sufficiently well situated on the shady side of the open court-yard of the French Consulate, about thirty feet above the sea level. The hours of observation were 8 A.M., 2 P.M., and 10 P.M.—not perhaps the best that could be selected, but sufficient in a climate where rapid transitions are unknown.
A few of the results here stated in Fahrenheit’s scale are derived from M. Beaumier’s tables as continued to the end of 1874:—
| Mean temperature during eight years | = | 66.9° |
| Do. for the hottest year (1867) | = | 68.65 |
| Do. for the coldest year (1872) | = | 65.75 |
| Mean of the annual maxima | = | 82.5 |
| Mean of the annual minima | = | 53.0 |
| Highest temperature observed | = | 87.8 |
| Lowest temperature observed | = | 50.7 |
More striking still is the comparison between the temperature of summer and winter. The following results show the monthly mean temperature, derived from eight years’ observations:—
| Summer | ⎧ ⎨ ⎩ | June | = | 70.8 |
| July | = | 71.1 | ||
| August | = | 71.2 | ||
| Winter | ⎧ ⎨ ⎩ | December | = | 61.4 |
| January | = | 61.2 | ||
| February | = | 61.8 |
showing a difference of only 10° of Fahrenheit’s scale between the hottest and coldest months. It has not been possible to ascertain accurately the daily range of the thermometer, as there were no self-recording instruments employed; but there is reason to believe that this would exhibit a still more remarkable proof of the equability of the climate. So far as the observations go they show an ordinary daily range of about 5° Fahr., and rarely exceeding 8° Fahr. It may be added, that in the course of six weeks from our arrival on April 26 to our departure on June 7, the lowest night temperature observed at Mogador was 61° Fahr., and the highest by day 77° Fahr.
If the climate of Mogador be compared with that of such places as Algiers, Madeira (Funchal), and Cairo, which have nearly the same mean winter temperature, it will be found that in each of those places the mercury is occasionally liable to fall considerably below 50°, and that the summer heat is greatly in excess of the limits that suit delicate constitutions, the mean of the three hottest months being about 80° Fahr. at Algiers, about 82° at Funchal, and 85° at Cairo. It will help to complete the impression as to the Mogador climate to say, that rain falls on an average on forty-five days in the year; and that, per 1,000 observations on the state of the sky, the proportions are
Clear 785; Clouded 175; Foggy 40: