According to the Barclays website, the exchange rate of U.S. dollars into euros is approximately 0.90 euros per dollar, as of July 2015. On the other hand, the Barclays exchange rate of British pounds into euros is approximately 1.39 euros per pound.
It is possible to purchase foreign currency from Barclays, but at a worse rate than the true exchange rate. For example, the price of purchasing euros with British pounds is approximately 1.32 euros per pound.
Barclays also provides updated graphs tracking the changing rates, including those over the course of one day and a variety of historic rates.