Letter | Published:

The Use of the Words “Weight” and “Mass”

Nature volume 13, page 466 | Download Citation

Subjects

Abstract

THE relations between weight and mass, gravity and acceleration, are so well defined in all good treatises on dynamics, that it appears superfluous to dwell on these questions. But as it has been stated by Prof. Barrett, vol. xiii., p. 385, that the C. G. S. system of units has been introduced into the course of Mechanics in this College, I may be permitted to say that the system actually employed is not that referred to by your correspondent. I generally employ the kilogramme, metre, and second, and sometimes the foot, pound, and second, to measure a dynam or unit of force. The dynamometers alluded to as about to be exhibited at the Loan Exhibition of Scientific Instruments at South Kensington are suitable to the former system, and I use them for the measurement of dynams in kilogrammetres. One of these dynamometers is graduated for every 200 grammes up to 100 kilogrammes, the other for every 100 grammes up to 10 kilogrammes, and they cannot be depended on for results within the tenth of a kilogramme. Spring dynamometers, though suitable for the large units employed in mechanics, are totally unfit for measuring units on the C. G. S. system. I concur with Prof. Everett, in his book on this system, when he says:—“A spring balance, it is true, gives a direct measurement of force, but its indications are too rough for purposes of accuracy” (p. 8). Spring dynamometers are therefore unsuited to a system where the units are measured by 1/981 of a gramme, or about 1/63 of a grain, as in the C. G. S. system.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Author information

Affiliations

  1. Royal College of Science for Ireland, Dublin

    • HENRY HENNESSY

Authors

  1. Search for HENRY HENNESSY in:

About this article

Publication history

Published

DOI

https://doi.org/10.1038/013466a0

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.