If the weather is stormy, the ice assumes all the appearance of waves

“To visit Langhorn and to relieve his distress, Ledyard crossed from Hamburg to Copenhagen, thus leaving the direct course to St. Petersburg, and, as you shall hear, increasing the distance many hundred miles. From Copenhagen he went to Stockholm, intending to cross over to Abo in Finland, and thus proceeding to the place of his destination.

“The manner in which the passage between Stockholm and the place I have just mentioned is made in the winter season, is so singular that I must describe it to you. The traveller, muffled up in furs, is seated on a sledge, which is drawn by two or three horses. The ice is sometimes so smooth that the passage is comparatively easy; but, if the weather is stormy, the ice assumes all the appearance of waves, and immense masses, heaped one upon another, offer the most fearful impediments. The sledge is frequently upset, and the horses sometimes become unmanageable and run away. When, however, there happens to be an open winter—one in which the frost is not sufficiently intense to freeze the passage entirely over, the water yet contains so much floating ice that no vessel can sail through it. This happened to be the case in the season in which Ledyard arrived, so that he found it necessary either to stay at Stockholm till the spring, or to proceed round the gulf, a distance of twelve hundred miles, over trackless snows, and in regions thinly peopled, where the nights are long and the cold intense, and all this to advance on his journey only about fifty miles.

Thomas Bingley: Tales about travellers - their perils, adventures, and Discoveries. 1841