Bob Hobden wrote:

I would like to get a 1/2in plastic pipe (for watering)
under the 3ft 6in wide granite-slab pathway in my front-garden.

Is there any clever way of doing this?

I have used a larger bore rigid plastic pipe to drill under a path to lay
electric cable from one side to another. Might work for you but depends on
the situation. I cut sharp points like saw teeth onto one end of the pipe
and a hole through the other end to take a "T" piece for a grip then
gradually pushed it through rotating it as it went to cut through the
soil

Thanks for all the suggestions.
I'll try this one first, and see how I get on.

--
Timothy Murphy
e-mail: gayleard /at/ eircom.net
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland