In fact, however, their construction can be traced in his logs and rationalized as several series of experiments which only produced his major instruments in the mid-1580's.
Sa katunayan, gayunman, ang kanilang mga construction ay maaaring traced sa kanyang mga logs at rationalized bilang ng ilang serye ng mga eksperimento lamang na kung saan ginawa ang kanyang mga pangunahing instrumento sa mid-1580 's.