require 'rubygems'
require 'spreadsheet'

book = Spreadsheet.open 'someFile.xls'
sheet = book.worksheet 'someWorksheet'

cells = []
sheet.each do |row|
  row.each do |cell|
    puts cell.value    # this raises the error: undefined method 'value' for "SUMMARY" String
  end
end


# in the interpreter ...

<< instance_of_a_cell.value
42