The Signal Service began observations in the early 1870s.

I then drew up my legs, which had been extended, and took a pencil in my hand to begin observations.

He lodged with two other hunters in a hunting cabin and did not yet begin observations or radio broadcasts.

"You're going to begin solar observations for flares in your first period after this meal?"

We have been attempting to hail the craft ever since we began visual observations.

Users expect to begin important observations in the next few months.

In the early 1820s, the army began meteorological observations at the fort.

Chad eyed the dinosaur and began muttering observations into his belt computer.

The post surgeon began meteorological observations at the fort in 1822.

And the next day they began observations which were destined to have surprising results.