Francesco Bianchini holding the <a href="https://en.wikipedia.org/wiki/eyepiece" class="extiw" title="w:eyepiece">eyepiece</a> mount of an  <a href="https://en.wikipedia.org/wiki/aerial_telescope" class="extiw" title="w:aerial telescope">aerial telescope</a>
<bdi><a href="https://en.wikipedia.org/wiki/en:Pier_Leone_Ghezzi" class="extiw" title="w:en:Pier Leone Ghezzi"><span title="Italian painter (1674-1755)">Pier Leone Ghezzi</span></a>
</bdi>
V. Kockel and B. Solch, Francesco Bianchini (1662–1729) und die europaische gelehrte Welt um 1700 (Berlin: Akademie Verlag, 2005), p. 21