The inscription hence records the construction of the tunnel; according to the text the work began at both ends simultaneously and proceeded until the stonecutters met in the middle. However, this idealised account does not quite reflect the reality of the tunnel; where the two sides meet is an abrupt right angled join, and the centres do not line up. It has been theorized that Hezekiah’s engineers depended on acoustic sounding to guide the tunnelers and this is supported by the explicit use of this technique as described in the Siloam Inscription. The frequently ignored final sentence of this inscription provides further evidence: "And the height of the rock above the heads of the laborers was 100 cubits." This indicates that the engineers were well aware of the distance to the surface above the tunnel at various points in its progression.