Abstract: Disclosed is an improvement in glass manufacturing methods of the type which involve providing water containing agglomerates of glass batch, heating the agglomerates by direct contact with furnace flue gases so as to dry them and increase their temperature, the heating being insufficient however, to cause the agglomerates to aggregate, transporting those heated agglomerates to a fossil-fueled melter and melting them in the melter. The improvement resides in the heating being done in at least two stages, the flue gases withdrawn from one stage, heat recovered therefrom and then the cooled flue gases being introduced into the other stage. The heat withdrawn from the flue gases may be employed for beneficial purposes.