| Carlo Marangoni | |
| Birth Date: | 29 April 1840 |
| Birth Place: | Pavia, Austrian Empire |
| Death Place: | Florence, Italy |
| Nationality: | Italian |
| Work Institutions: | Liceo Dante, Florence |
| Alma Mater: | Università degli Studi di Pavia |
| Doctoral Advisor: | Giovanni Cantoni |
| Known For: | fluids, capillary, surface tension |
Carlo Giuseppe Matteo Marangoni (29 April 1840 – 14 April 1925) was an Italian physicist.
Marangoni graduated in 1865 from the University of Pavia under the supervision of Giovanni Cantoni with a dissertation entitled "Italian: Sull' espansione delle gocce liquide" ("On the spreading of liquid droplets").
He then moved to Florence where he first worked at the "Museo di Fisica" (1866) and later at the Liceo Dante (1870), where he held the position of High School Physics Teacher for 45 years until retirement in 1916.
He primarily studied surface phenomena in liquids, and the Marangoni effect and the Marangoni number are named after him. He also contributed to meteorology and invented a Nefoscopio to observe clouds.
Marangoni simplified the aspirator for the measurement of gas. A common flaw in aspirator were inaccurate measurements caused by ascending of air or gas through descending liquid. The perfected device uses a couple of vessels attached to a fixed horizontal shaft, FE, which rests on two erect supports. The shaft has various passages which conducts the functions of the taps. The water of the above receptacle releases into the bottom receptacle by passage A, and through the tube, BC, issuing at the lowest extremity at C. The air within the bottom vessel is omitted by the passage DE, cut into the shaft, meanwhile the air or gas is aspirated in the identical ratio by the passage, FG.[1]