Abstract

A reading-lens for burettes and thermometers is described in which errors due to parallax are eliminated by an ocular slit at a distance in front of the lens equal to its focal distance. Spring clips above and below the lens tube give a high degree of rigidity combined with applicability to a wide range of burette or thermometer diameter. For reading the lowest point of the meniscus in burettes filled with a colorless liquid, a spring of sheet brass holds against the back of the burette a suitable ruled background. Two types of background are described, giving either maximum ease and precision of reading, or else, by obviating the necessity for an accurate placing of the reading lens, speed.

© 1926 Optical Society of America

A High Temperature Thermometer

Sylvester Boyer
J. Opt. Soc. Am. 13(1) 117-122 (1926)

Some Defects of Clinical Thermometers

Bradford Noyes
J. Opt. Soc. Am. 13(2) 223-228 (1926)

An Optical System for Reading the Angular Deflection of a Mirror*

I. C. Gardner
J. Opt. Soc. Am. 12(5) 529-536 (1926)

A Direct Reading Burette1

Albert M. Jackson
J. Opt. Soc. Am. 7(6) 491-494 (1923)

A Direct Reading Tacheometer

W. H. Connell
J. Opt. Soc. Am. 13(4) 503-508 (1926)