As late as the mid-18th century, the ex-slave Olaudah Equiano, in his autobiography "The Interesting Narrative of the Life of Olaudah Equiano", documented the use of thumbscrews to torture slaves. During this period (mid-18th century), Thomas Clarkson carried thumbscrews with him to further his cause for the abolition of the slave trade and later emancipation of slaves in the British Empire. He hoped to, and did, inspire empathy with the display of this and other torture devices used on slaves. They were used on slave ships, as witnessed and described by Equiano and Ottobah Cugoano.