36 PASSAGE FROM MADEIRA 



shoal water, or danger of any kind. Here we experienced westerly 

 winds, and took advantage of them to make easting. After we had 

 lost the trades, in latitude 12° N., I observed, when the upper stratum 

 of clouds could be seen, that they were passing from east-northeast, 

 with rapidity to the westward. 



We now ran for the French Shoal, in latitude 4° 5' N., longitude 

 20° 35' W. Here the wind inclined to the southward, and we pro- 

 ceeded as far east as longitude 13° W., passing over the two positions 

 laid down by the French and English hydrographers, but saw nothing 

 of it. 



We now tacked to the southward, to cross the equator in longitude 

 17° W. The weather had changed, the rains which we had expe- 

 rienced at night ceased, and the extremely indistinct atmosphere 

 which at times had prevailed for the last fortnight, disappeared. It is 

 difficult to describe the peculiar effect this haziness produced. It 

 seemed to me an effect the opposite of that of looming, apparently 

 diminishing all objects. Although the horizon was seen, yet the sea 

 and sky w 7 ere so blended together, that it was difficult for the eye to 

 fix upon or define it at any moment. It was impossible to use the dip 

 sector. At the same time it was perfectly clear over head, with a 

 bright sun, and the upper cirrus clouds, when seen, were in rapid 

 motion to the westward. 



The quantity of rain that fell between 9° 30' and 5° north latitude, 

 was 0-1 5 inches during ten days. The greatest fall in twenty-four 

 hours was 1-95 inches. The temperature of the rain on several trials 

 varied from G9° to 72°, that of the air being at the time 77°. 



The nights were now beautiful until near morning, when it generally 

 clouded over, and remained overcast with flying clouds until evening. 

 The zodiacal light w r as once or twice observed, but the presence of 

 these clouds for the most part prevented it from being seen. 



On the 29th, in latitude 3° 40' N., our observations gave a current of 

 ten miles in twenty-four hours, to the north. Until the 3d of November 

 we had light winds ; the upper stratum of clouds was now seen moving 

 from the east. On the 4th w r e had a cry of breakers from the mast- 

 head. We immediately changed our course and ran for the appear- 

 ance, but it proved on nearing it to have been one of the many optical 

 illusions seen at sea, from the effect of light and shadow. 



On board the Peacock, on the 30th of October, in latitude 1° 30' N., 

 longitude 18° W., they witnessed a remarkable appearance, resembling 

 the aurora borealis, radiating from the northwest point of the horizon 

 in different directions, and extending from southwest round by the 

 north to the eastward, at an altitude of from 10° to 50°; afterwards 



