Gies, Frances. <br/><br/>
Cathedral, forge, and waterwheel :  Technology and invention in the Middle Ages / 
Frances & Joseph Gies. 
 - New York :  HarperCollins Publishers,  1994. 
 - 357 p. :  ill. ;  22 cm. 
<br/><br/> Includes bibliographical references and index. 
<br/><br/><label>ISBN: </label>9780060165901:  Ksh 2,500/= 0060165901 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Technology--History.<br/>Inventions--History.<br/>Science, Medieval.
<br/><br/><label>LC Class. No.: </label>T17  / .G5