I saw in Cohasset, separated from the sea only by a narrow beach, a very large and handsome but shallow lake, of at least four hundred acres, with five rocky islets in it; which the sea had tossed over the beach in the great storm in the spring, and, after the alewives had passed into it, stopped up its outlet; and now the alewives were dying by thousands, and the inhabitants apprehended a pestilence as the water evaporated. The water was very foul.[262] The rockweed is considered the best for manure. I saw them drying the Irish moss in quantities at Jerusalem Village in Cohasset. It is said to be used for sizing calico. Finding myself on the edge of a thunder-storm, I stopped a few moments at the Rock House in Cohasset, close to the shore. There was scarcely rain enough to wet one, and no wind. I was therefore surprised to hear afterward, through a young man who had just returned from Liverpool, that there was a severe squall at quarantine ground, only seven or eight miles northwest of me, such as he had not experienced for three years, which sunk several boats and caused some vessels to drag their anchors and come near going ashore; proving that the gust which struck the water there must have been of very limited breadth, for I was or might have been overlooking the spot and felt no wind. This rocky shore is called Pleasant Cove on large maps; on the map of Cohasset alone, the name seems to be confined to the cove where I first saw the wreck of the St. John alone.[263] Brush Island, opposite this, with a hut on it, not permanently inhabited. It takes but little soil to tempt men to inhabit such places. I saw here the American holly (_Ilex opaca_), which is not found further north than Massachusetts, but south and west. The yellow gerardia in the woods. _July 26._ At Cohasset.—Called on Captain Snow, who remembered hearing fishermen say that they “fitted out at Thoreau’s;” remembered him. He had commanded a packet between Boston or New York and England. Spoke of the wave which he sometimes met on the Atlantic coming against the wind, and which indicated that the wind was blowing from an opposite quarter at a distance, the undulation travelling faster than the wind. They see Cape Cod loom here. Thought the Bay between here and Cape Ann thirty fathoms deep; between here and Cape Cod, sixty or seventy fathoms. The “Annual of Scientific Discovery” for 1851 says, quoting a Mr. A. G. Findley, “Waves travel very great distances, and are often raised by distant hurricanes, having been felt simultaneously at St. Helena and Ascension, though 600 miles apart, and it is probable that ground swells often originate at the Cape of Good Hope, 3000 miles distant.” Sailors tell of tide-rips. Some are thought to be occasioned by earthquakes.