Atoms minute or letters thin—
To give appearance of fair size,
Though naked unassisted eyes
Can scarce perceive them. Grains of sand
Seem stones when through these glasses scanned.”
The poet adds that by these glasses one can read letters from such a distance that one would not believe it unless he had seen it. Then he concludes:
“But to these matters blind affiance
No man need give; they’re proved by science.”
Theories formed by experimenters with lenses.
Returning to Grosseteste and experimental method we may note his mention in the same treatise upon comets of “those who reflect and experiment in natural phenomena and form their opinions from their experiments without foundation of reasons.”[1443] Grosseteste holds that such experimenters “necessarily fall into false notions concerning the natures of comets,” because they try to explain them as reflected rays and the like after the analogy “of their varied experiments which they have employed in radiations and the producing of fires”—probably by burning glasses—“and by what is seen through the medium of lenses” (diaphanorum). The important point for us, however, is not whether these men were wrong about comets, but their varied experimentation and their basing of hypothesis upon their experiments.