This book has been written for the practical worker in optics rather than for the student or general reader. It deals with optical instruments and optical measurements and "is intended for the man in the field designing instruments, measuring color, examining eyes, identifying illuminants, etc." It is essentially a manual of mathematical formulas for working out the problems indicated in the above quotation. Unfortunately, we are unable to criticize all portions of the work with equal assurance but would call attention to the following on page 115.
"The limits of accommodation are by no means the 25 cm. to infinity ordinarily taken as the limits of the normal visual distance. The normal eye, even at middle age, can easily accommodate itself to an object beyond infinity, i. e., a meter behind the eye, or as near as 10 cm. in front of the eye. The power of accommodation decreases considerably,