Syismometer or Seismometer: How To spell?

The word Syismometer is misspelled against Seismometer, a noun meaning "An instrument for measuring the direction, duration, and force of earthquakes and like concussions."

Word contains consecutive vowels 'EI' in between alphabets s & smometer is misspelled as 'YI'
Wrong Spelling:  s-yi-smometer 
Correct Spelling:  s-ei-smometer 
Find more incorrect spellings of Seismometer to spell right way.