1. Electronic triple-axis gyro with accurate attitude control and artificial horizon.

2. The company outfitted him with a sextant, an artificial horizon, compass, thermometers, watches, Nautical Almanacs, and all the instruments and supplies necessary to carry out his surveying.

3. It still has to be analysed if these birds would refer to the azimuth and altitude of their stellar orientation pattern with the natural or an artificial horizon as the primitive circle.