266 LISTEN TO YOUR WISER SELF! Shopping's done and you've a few shillings to spare. Going to let them burn a hole in your purse? Listen to your wiser self saying " Of course not! You've saved a fair amount already through your Street Group. Surely you're not going to stop now! Keep on with the good work—keep on buying National Savings Certificates." Every 15/- Certificate earns you 5/6 in 10 years' time. This increase is not subject to Income Tax. BECAUSE They're easy to buy, easy to hold, easy to cash.