This is an interesting resource, and very speedy to browse, or to search
[ especially if one uses DuckDuckGo ]
https://etc.usf.edu/clipart/
Many of the images are available in usefully high resolution:
https://etc.usf.edu/clipart/46600/46695/46695_rain_gauge.htm
for example.
… and are free for non-commercial use.
MichaelG.
.
Edit:_ for anyone who happens to be interested in the Rain Gauge … there is a fuller description of it here:
https://www.gutenberg.org/files/41351/41351-h/41351-h.htm#Page_11