When I read Belcastro’s & Yackel’s book Making mathematics with needlework I not only made some torusses for my nephew to chew on but was inspired to convert “Fortunatus’ Purse”, which originally is sewn, into knitting.

I got some hints from Sarah-Marie Belcastro and started a test-knit. I made a small hat which has been photographed on Eugene, my old teddy-bear. He can wear it in umpty ways.

My husband who is a physicist wants to have a Fortunatus hat for himself but there are other projects in the row - a long and winding row.

When I have finished I will make some remarks about the construction that bases on a Moebius. I made some expressive pictures which will show the details.