Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne
October 21 - October 28

Question of the Week

Name: Rod
Status: other
Grade: other
Country: Australia
Date: Winter 2013-14 


I am trying to find out the name of an instrument on a rotatable pole with a rake like head which we used at air bases (RAF Kinloss, Scotland) to measure the speed of clouds overhead by timing how many points on the rake passed in so many seconds. (In the 1960's)

Answers from Our Expert Staff

Measuring the speed of the movement is not easy. Indeed, it borders on the impossible. The website: gives you some reasons, but it is not a total list of cloud forms. A cloud doesn?t have a rigid form, so at one location it can move in 3 dimensions. Clouds come and go, depending on temperature and relative humidity or the dew point. These variables depend upon the speed of the atmosphere and its temperature. It is relative easy to measure large clouds, e.g. hurricanes, tornados, etc. because those clouds reflect cloud forms. But instruments that measure less water become not so useful for thin clouds.

Vince Calder

Past Questions of the Week

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory