use the following code:
births <- scan("http://robjhyndman.com/tsdldata/data/nybirths.dat")
plot(births)
plot.ts(births)
It is an example data set of the number of births per month in New York city, from January 1946 to December 1959 (originally collected by Newton). This data is available in the file http://robjhyndman.com/tsdldata/data/nybirths.dat