Misc: what's spaceball played on?

Questions

What was the principal wood used by Thomas Chippendale during the 18th century?

What name is given to the art of dwarfing trees?

In which Shakespeare play would you find Constable Elbow?

What name is given to a marriage in which the wife does not acquire her husband's rank and the offspring do not inherit the title?

The Albert Canal links Liege with which city?