Laser levels - why not just use a ball of string?

Hmmm .... I'm of the opinion that we are _both_ thinking of a pier that's _horizontal_ ( = tangential to the Earth's Surface and at a constant height above mean-seal-level) at all points on the pier's surface, both at the middle and the end. {Give or take the tolerances available to the builders). Would you care to rethink your 'interesting' theory? would you care to try to determine it's 'horizontal-ness' with a ball of string?

Note the 'weasel word' (allegedly): I re-used the figure given in the original post. You may be, or not be, correct ... as I'm unlikely to stand on this Antipodean Pier, nor likely to be bamboozled by a Strine Guide (somewhat similar to a Strain Gauge but less accurate) I don't really care how fast it conveys nor how undulating its surface is. I'll await the development of the "during the day the tremendous heat causes the end to expand and touch the Sky'; next episode .... :)