DERIVATIVES OF CHAPPE The position of the towers did not allow the transmitted message to be visible from all angles. The Spanish Betancourt and Mathé were the ones that allowed the greatest viewing angle (more than 45º), much higher than that of Chappé’s telegraph, which is why both systems would be highly praised in scientific circles on the continent. However, there was a major drawback: at night they were unreliable and although experiments were carried out attaching lanterns to the signaling elements of the telegraphs, none of the prototypes would pass the test with satisfactory results. On the other hand, adverse weather conditions such as rain, snowfall or fog caused the transmission to stop and wait for these conditions to improve on the days until visibility was allowed.