Sismoscope or Seismoscope: How To spell?

The word Sismoscope is misspelled against Seismoscope, a noun meaning "A seismometer."

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