We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Bruce saying something like:
Exactly so. I used one to put in a floor from scratch where the level was fairly important because of a floor-level window at one end. At the time laser levels were still fairly pricey and this cost about 3 quid for the aquarium air tubing. Worked a treat, and I suppose it's possible there might be up to 3mm error, in practice it's certainly not noticeable.