As the nineteenth century drew to a close, scientists could reflect with satisfaction that they had pinned down most of the mysteries of the physical world: electricity, magnetism, gases, optics, acoustics, kinetics, and statistical mechanics, to name just a few, all had fallen into order before them. they had discovered the x ray, the cathode ray, the electron, and radioactivity, invented the ohm, the watt, the kelvin, the joule, the amp, and the little erg.

if a thing could be oscillated, accelerated, perturbed, distilled, combined, weighed, or made gaseous they had done it, and in the process produced a body of universal laws so weighty and majestic that we still ten to write them out in capitals: the electromagnetic field theory of light, richter’s law of reciprocal proportions, charles’s law of gases, the law of combining volumes, the zeroth law, the valence concept, the laws of mass actions, and others beyond counting. the whole world clanged and chuffed with the machinery and instruments that their ingenuity had produced. many wise people believed that there was nothing much left for science to do.

source: bryson, bill. “einstein’s universe.” a short history of nearly everything. new york: broadway, 2003. 115. print.

which of the following represents the author’s purpose in this excerpt best?

to persuade
to instruct
to record
to reflect