Sismograph or Seismograph: How To spell?

The word Sismograph is misspelled against Seismograph, meaning "An instrument for recording the phenomena of earthquakes."

Word contains consecutive vowels 'EI' in between alphabets s & smograph is misspelled as 'I' as letter 'E' is phonetically igno
Wrong Spelling:  s-i-smograph 
Correct Spelling:  s-ei-smograph 
Find more incorrect spellings of Seismograph to spell right way.