Theory of Cost and Production Functions . By R. W. Shephard. Princeton: Princeton University Press, 1970. Pp. xi, 308. $15.00.

This Guide to more than two and one-half million manuscripts covers mainly the personal and business papers of the Du Ponts, from the eighteenth to the twentieth centuries. Anyone interested in the Du Ponts need look no further, because archives in Europe and the United States have been combed and pertinent material copied and listed here. There are also papers of others closely connected with the family or the firm, such as John J. Raskob. The non-Du Pont manuscripts relate particularly to the economy of the Delaware Valley. This Guide is unusual in its detail. Whereas most published library guides devote only a paragraph or two to each collection, this one is more a calendar or index. The detailed listings make it possible to use the manuscripts from many points of view. Any extensive archive of an individual or organization that has played an important role has this potential, but many do not realize it. Under-utilization should not be a problem at Eleutherian Mills. For each of the Du Ponts whose papers are represented here, there is a chronology and a bibliographical note referring to published sources. Both recipients and writers of letters are listed, with an indication of the years of the correspondence and the number of letters. For manuscripts which are not letters, and sometimes even for them, there are informative descriptions of the contents. If it could be determined that a manuscript has been published, a citation is given. A 200-page index provides ready access to the collections by name and sometimes by subject and place name. The only warning to be noted is that French names which include the prefix de or d' are listed under the prefix and without a cross reference. Mr. Riggs and his colleagues deserve congratulations and thanks for a wellplanned and executed work of great value to historians of both France and the United States.