These are the show notes for episode 49 of the Travels in a Mathematical World Podcast. 49 is the number of strings on a harp. More about 49 from Number Gossip.

In the week in which this episode is released I am giving the first in hopefully a series of lectures entitled “History of Maths and x”, for various x. I am no expert on these topics but they interest me and I would like to explain a little of them to you. This time the x is cryptography and the lecture covers “Substitution ciphers: Ancient – Renaissance”. Lectures take place at the University of Nottingham. The lecture was videoed for the web and can be downloaded at History of Maths and x. Lectures are to be accompanied by an article in iSquared Magazine and a companion episode of this podcast containing additional information not in the talk or article.

You can view the talk and find out more through www.historyofmathsandx.co.uk.

You can find out more about my work with the IMA by following me on Twitter, reading this blog and visiting http://www.ima.org.uk/student/. Join the Facebook page.