A small portable PVC mortar used to fire mini marshmallows. Easy to build.
Step 1: Parts list
a long length of 7/8 inch diameter sch. 40 pvc pipe
2 elbow couplings
1 threaded end cap adapter
1 4 way coupling
2 end caps
Oh and most importantly, you'll need the red thing of of this weird cone ball game from like the 60's