Found by Dave Buckingham, October 1972. A number of them have periods which are not a multiple of 4. The following p78 frothing puffer was found by Paul Tooke in April 2001. Found by Dean Hickerson in September 1989. For examples, see baker , beacon maker , blinker ship , boat maker , cow , harvester , lightspeed wire , pi ship , reverse fuse , superstring and washerwoman .
Useful fuses are usually clean .