VANEK: V tom clanku jsou dalsi perly:
"Occasionally, surveyors must use one foot for horizontal measurements and the other for elevations. That happened to Dr. Dennis on an engineering project in Arizona. But while the geospatial software was capable of acknowledging both feet, it would not allow for different feet in different directions. He resolved the problem by converting everything to international feet and massaging the vertical measurements, which ought to have been in U.S. survey feet."
"Even the National Geodetic Survey gets muddled. In a video about how not to mix up the two feet, it mixed them up. It wrongly said that 2,000 meters was 6,561.67 international feet and 6,561.68 U.S. survey feet, reversing the correct conversions. The error went unnoticed for years until Dr. Dennis watched the video recently as he plotted to kill the old foot. He was mortified."