div class=ts-pagebutton class=gotoPage data-page=1Page 1button div class=ts-imageimg data-url=an-acoustic-method-whereby-the-depth-of-water-in-a-river-may-be-measured-athtmlpage=1 data-page=1 class=ts-thumb lazyload alt=Page 1: An Acoustic Method whereby the Depth of Water in a River may be measured at a Distance loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader036vdocumentssitereader036viewer2022080320575067981a28ab0f07ac4209html5thumbnails1jpg width=140 height=200 divp© 1892 Nature Publishing Grouppdiv