An Exercise in Paper Folding
The following comes from the book, How ? (or Spare Hours Made More Profitable for Boys and Girls), published in 1887. The plot thickens around Figure 7, but with a little luck, I'm sure you can do it. (Be patient. The instructions take a short time to load as they are GIF images of the book's pages, but hopefully in the time it has taken you to read this they have loaded).
While the instructions call for a 3 inch x 4 inch piece of paper, I've found the US standard 8.5 inch x 11 inch works just fine. (In fact it's easier with larger paper).I suspect A4 would do just fine also.
While I like the above, as they were printed in the midst of the Paper Boat era, you can find some even more detailed step-by-step instructions with photographs of how to do it! (click here).
And for extra credit, you could try a 19th Century Paper Hat.