From the Oxford English Dictionary:
spell
• verb (past and past part. spelled or chiefly Brit. spelt) 1 write or name the letters that form (a word) in correct sequence. 2 (of letters) make up or form (a word). 3 be a sign of; lead to: the plans would spell disaster. 4 (spell out) explain clearly and in detail.
Oggy and Jimbo are both correct.
spell
• verb (past and past part. spelled or chiefly Brit. spelt) 1 write or name the letters that form (a word) in correct sequence. 2 (of letters) make up or form (a word). 3 be a sign of; lead to: the plans would spell disaster. 4 (spell out) explain clearly and in detail.
Oggy and Jimbo are both correct.
blower

