Letter: Unobtainable

Sir: Your report (7 July) on a motorist who used her mobile phone to summon help after she fell down a cliff in Cornwall may have given the impression that such phones are everywhere effective.

The two I have tried malfunctioned here in south Warwickshire, where we have no cliff, and this prompted me to ask for a coverage map - no longer available. So I asked the network HQ (by landline) about several places in Wales and Scotland which I visit, and was told they were all in dead zones.

Many people are persuaded to have such a phone as a standby for emergencies, but the coverage claimed for them is a proportion of population, not of land area.

I am wondering whether a Very pistol might be more reliable as a means of summoning aid.

PETER HILL

Tanworth-in-Arden, Warwickshire