A major assumption of the syllable-timing/stress-timing distinction is that interstress interval length in a language like French is a direct additive function of the number of syllables it contains. In stress-timed languages like English, by contrast, interstress interval length is supposed to show a relationship of negative acceleration with increasing syllable number due to an underlying tendency towards the isochronous spacing of stresses. Nakatani et al. (1981), however, showed that interstress intervals are not only positively correlated with intervening number of syllables, there is also no relationship of negative acceleration between foot size in syllables and foot duration. Acoustic timing data for French concur with Nakatani et al.'s findings for English. Accentual phrase duration was highly correlated with the number of syllables that unit contained. Although disyllabic units were not twice as long as monosyllabic units in these French data, this could reflect the fact that rhythmic units in French include a long final syllable due to a right boundary accent. The similarity of these results and those for American English would suggest that apparent compression effects are not a strong argument in favor of one typological description as opposed to another. A further experiment revealed lengthening patterns associated with phrasing that are hierarchical in nature and are compatible with recent models of intonational phrasing proposed for French (e.g., Martin, 1987) and highlight the relevance of accentual grouping in descriptions of French timing.