  We report on the first frequency ratio measurement of an $^{115}$In+ single
ion clock and a $^{87}$Sr optical lattice clock. A hydrogen maser serves as a
reference oscillator to measure the ratio by independent optical combs. Over
more than 90 000 seconds of measurement time, the frequency ratio
$f_{\rm{In^+}}/f_{\rm{Sr}}$ is determined to be 2.952 748 749 874 863 4(21)
with relative uncertainty of $7.0 \times 10^{-16}$. The measurement creates a
new connection in the network of frequency ratios of optical clocks.
