x = 49, y = 27, rule = B34/S34
3boboobobo$bob4obo$oobb3obo3bo$oobb3obo3bo$bob4obo$3boboobobo12$8bo27b
o$16b3o6boo17bo$3bob3o3bobo5bobobboboo3bob3o3bobo4bo$bob7o3boobooboboo
3b4ob7o3boobobobo$oobboo3boo3boboobb3o3bobbobboo3boo3bo3bobo$oobboo3b
oo3boboobb3o3bobbobboo3boo3bo3bobo$bob7o3boobooboboo3b4ob7o3boobobobo$
3bob3o3bobo5bobobboboo3bob3o3bobo4bo$16b3o6boo17bo$8bo27bo!
This shows two related period 3 spark-producing spaceships.
The second one can be made arbitrarily long.
David I. Bell, February 1994
