Sailing through Kendal Dyke, which in places was so narrow that the _Swan_ brushed the reeds on both sides as she passed through, they reached the Hundred Stream, and, turning to the south-westward, they sailed, with no further adventure, until they came to Heigham Bridge, where they had to lower their masts in order to get through. While Frank and Jimmy did this, Dick took his butterfly net, and went after an orange-tip butterfly, which he saw flying past. This butterfly is one of the first which makes its appearance in the spring, and it is one of the prettiest. It looks as if a bunch of red and white rose petals had taken to themselves wings and fled. It is a small butterfly, having an orange-red tip on the ends of its forewings. The male only has this ornament. The female has only a greyish black tip. The under surface of the wings of this pretty insect is no less beautiful than the upper. It is white, with bright green marblings, or what appear as bright green to the naked eye. When looked at through the microscope it will be found that the green appearance is caused by the mixture of black and bright-yellow scales. (I suppose that most of my boy readers will know that the dust which is so easily rubbed off a butterfly's wings is in reality a coating of scales arranged one over the other like feathers and of very exquisite shapes.) The caterpillar of the orange-tip is green, with a white stripe on each side, and the chrysalis is very peculiar in shape, tooth-like, and pointed at both ends. [Illustration: ORANGE-TIP BUTTERFLY.] Dick was a long time away; and when he came back, flushed with exercise, he had no less than eight orange-tips in his net, which he proceeded to kill and set there and then. They sailed on very slowly, for the breeze had fallen, until they came to the Thurne Mouth, and then they turned up the Bure until they came to St. Benedict's Abbey, the ruins of which stand on the northern bank of the river. Here they determined to camp for the night, and accordingly ran their boat into a marshy creek, and made her fast to the reeds. They were much amused at the remarks of the people whom they passed, whether on the bank or on board the wherries and yachts. The like of the _Swan_ had never before been seen on Norfolk waters. She was a _rara avis in terris_ and excited any amount of appreciatory and depreciatory comment. After making the boat snug and comfortable, the boys proceeded to cook their dinner. They brought out from the lockers some cold beef and ham, and boiled the potatoes in a small tin saucepan over the spirit-lamp. The meal was soon ready, and they sat down to it with most excellent appetites. "Where have you put the salt, Frank?" asked Dick. "The salt?" replied Frank, thoughtfully. "Yes, the salt." "Well, let me see. Dear me, we must have forgotten it." "But Frank, how can you--how can anybody eat beef without salt?" said Jimmy reproachfully.