Apart from its height, Salisbury Cathedral spire
is estimated to be about four and a half feet --- sorry, 1.5 metres --- out of the vertical. It's not clear whether this has always been the case, from the date of its construction, or whether the tilt has happened over subsequent centuries because of subsidence
In any case, if you go to the place where the north and south transepts cross the main aisle, stand next to one of the four enormous marble pillars which support the tower and the spire above you, and then bend down and squint directly upwards along the pillar itself, you can see a definite twist in the marble cylinders as they ascend.
Doing this has always made me feel slightly uneasy (and vertiginous), regardless of the time over which the cathedral and its spire have remained perfectly stable. It also reminds us, in this mechanised age, of the phenomenal skills and physical courage employed by its mediaeval builders --- master masons, stonemasons, and casual labourers unassisted by tower cranes or anything much else, really --- in putting this huge and beautiful building together.
Here's a final thought:-
Make some kind of estimate of England's GDP over the period when Salisbury cathedral was being built (to the glory of God but also, of course, as a symbol of ecclesiastical power).
Then take another rough shot, at the percentage of this GDP which must have been expended upon doing so.
Now let us ask ourselves:- Supposing we were to apply the same percentage of GDP, today, to the erection of a building such as the headquarters of a bank? What kind of monumental work could we achieve?
It would, I think, be staggering. The most prestigious building you can think of in Britain or indeed the world --- including, for instance, the Kennedy Space Center at Cape Canaveral, which we might perhaps consider one of our great secular temples --- would surely look fairly pathetic when compared in terms of relative cost, in cash and human endeavour, with Salisbury or any of the great mediaeval cathedrals.