212 THE NATIONAL SAVINGS MOVEMENT 
ten years its value was 24s. instead of the 26s. under certificates 
of the first and second series. 
On Savings Certificates of the first series which cost 15s. 6d. 
each no interest was paid if the certificate was cashed during 
the first year. On the completion of the first twelve months 
the cash value increased by 3d., and thereafter by 1d. a month 
up to the end of the fifth year, when an additional 8d. made 
the cash value £1. Originally it was a five years’ security, 
but the period was extended to ten years, interest being 
allowed at the rate of 1d. per month, with an additional 1Is., 
making 26s. in all, at the end of the tenth year from the date 
of purchase. The price of the second series of certificates was 
increased to 16s.—a much more convenient price to deal with 
than the original 15s. 64. No interest at all was allowed on 
account of the first year, but thereafter, throughout the whole 
lifetime of the certificate, the interest was 1d. per month with 
an additional shilling at the end of ten vears. making the value 
at maturity 26s. 
The third series of certificates, introduced on 1st October 
1923, gives 3d. for interest on certificates that have been in 
force for a full year. Thereafter the interest is 3d. every four 
months, or 9d. a year, up to the end of the tenth year, when an 
additional shilling is added, making the value of the certificate 
at maturity 24s. 
The rate of interest per cent. per annum yielded by certifi- 
~ates at the end of ten years is for the first series 5-309, for the 
second series 4°975, and for the third series 4-138. The rates 
of interest here quoted are those at which the purchase price, 
if accumulated at interest compounded annually, would 
amount to the cash value. Thus, a certificate costing 16s. or 
192 pence, and yielding 26s. or 312 pence at maturity, gives the 
formula, 312 + 192 =(1 +4)! whence (log 312 -log 192) + 10= 
log (1+¢), where ¢ is the interest on 1 for one year. The 
rates of interest for intermediate vears are found in the same 
way. 
There is no doubt about the attractions of Savings Certifi- 
cates from an investor’s point of view, but it is worth considering