| Before the end of that century, astronomers knew the answer to that question, thanks to spectrography. |
| Peirce was an acquaintance of Henry Rowland and, like him, conducted research on color spectrography. |
| Their concentration in the gold after parting can be determined by arc spectrography. |
| Left foreground: hydraulic press used to press into pellets with potassium bromide the samples for infra-red spectrography. |
| A fortuitous recent result of asteroidal spectrography found that the object under observation was, in fact, a nearly dormant comet. |
| From closer in, or with the planet eclipsing the sun, he would be able to get a spectrography of the atmosphere. |
