GAS LIQUID CHROMATOGRAPHIC ANALYSIS OF FATTY ACIDS IN FOOD RESIDUES FROM CERAMICS FOUND IN THE SOUTHWESTERN CAPE,SOUTH AFRICA

Gas liquid chromatography was used to analyse residues adhering to the inside of excavated potsherds from dated South African sites. The results suggested marine animal fat, possibly seal, had been cooked in the vessels. Fat of modern seals was baked and also analysed as a control sample. This gave similar results. The importance of seals in the prehistoric diet of the Southwestern Cape is supported by a large number of seal bones in the associated faunal material.     

Toward Conceptualizing Trip-Chaining Behavior: A Review

This paper critically reviews the existing literature on multiple-trip journeys, and clarifies the need for an improved conceptualization and modeling strategy. It also suggests different ways that trip chaining can be treated and a theory constructed. Exploratory studies, from the 1960s and 1970s, are briefly surveyed (Section I). While they developed the existence and complexity of travel patterns, they lacked any comprehensive theoretical framework. However, they were useful in that they supported the conceptual framework of various kinds of stochastic processes used by transportation scientists to replicate trip-chaining behavior (Section II). Scientists subsequently improved their conceptualization of the issue by grounding individual behavior on the principle of utility maximization. In this latter area the economists have emphasized theoretical concerns while transportation researchers have emphasized operationality (Section III).     

Book reviews

Reappraisal of a Road Project in Iran. By Herman G. Van Der Tak and Jan de Weille. (world Bank Staff Occasional Papers, No. 7). Baltimore, Maryland: The Johns Hopkins University Press, 1969. 127 pp. $3.00.

The Economic History of the Middle East, 1800–1914: A Book of Readings. Edited by Charles Issawi. Chicago: University of Chicago Press, 1967. xv + 543 pp. $12.50