         DU = Image
     data = new DU(header, @view, @offset)
     
-    excess = File.excessBytes(data.length)
+    excess = @excessBytes(data.length)
     
     # Forward to the next HDU
     @offset += data.length + excess

  
  # ##Instance Methods

  # Extracts a single header without interpreting each line.
  # Interpretation is slow for large headers.
  readHeader: ->

      break if done
      
      # Grab a 2880 block
      block = @view.getString(@offset, @BLOCKLENGTH)
      @offset += @BLOCKLENGTH
      
      # Set a line counter
      i = 0
      loop
        # Search for the END keyword starting at the last line of the block
        start = @BLOCKLENGTH - @LINEWIDTH * (i + 1)
        end   = @BLOCKLENGTH - @LINEWIDTH * i
        line  = block.slice(start, end) # Is this expensive?
        
        # Search one line up if white space is matched
