A widely applicable and rapidly computed method for estimating the maximum tangential wind speed in a tornado is developed. The method requires knowledge of the cloud deck height and the descent distance of the funnel cloud tip (often available from still photographs). The method is applied to the Dallas tornado of Apr. 2, 1957 , and yields a maximum swirling speed of 209 mi hr-1. Previous estimates for that whirlwind were 170 mi hr-I (based on scrutiny of motion pictures of flying dust and

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... is) and 302 mi hr-1 (based on studying damage inflicted on structures and vehicles).