74 THE SWISS FAMILY ROBINSON
and throw it across,' suggested Ernest. ' Then we shall know exactly.'
It was a good thought, and answered admirably. By this method we found that the distance from one side to the other was eighteen feet. Allowing three feet more for the part of the planks that was to rest on each bank, I reckoned we ought to have planks twenty-four feet long, and I found that many we had brought were about this length.
There now remained the difficulty of carrying one end across the stream ; but we determined to discuss this while we had lunch, which had been waiting for us more than an hour.
We therefore turned homewards and found that my wife had prepared for us a large dish of lobsters; but before beginning she insisted we should look at something she had made. It was two sacks intended for the donkey; these she had sewed together with thread, so that they might act as panniers or bags to hang on both sides of his back. I was very glad to see them as they would be most useful in transporting our household stuff when we moved.
We hurried through our meal, being deeply interested m the work we were about to undertake.