[O] mnis rationalis opinio de velocitate motuum ponit eam sequi aliquam propor-
tionem: hec quidem proportionem excessus potentie motoris ad resistentiam seu
potentiam rei mote, alia vero proportionem resistentiarum manente eadem
potentia motiva vel equali vel proportionem potentiarum activarum manente resistentiavel equali, tertia proportionem potentie motoris ad resistentiam seu potentia rei mote
This sample covers the first five lines of De proportionibus. Grant translates the passage as follows:
Every reasonable opinion about velocity of motions assumes that it follows some ratio. One opinion is [that velocity of motion follows] a ratio of the excess of the power of the motor to the resistance or power of the thing that is moved; another opinion supposes that velocity follows the ratio of resistances with the power remaining constant or equal, or [follows] the ratio of the powers with the resistance remaining constant or equal; a third opinion [assumes that velocity of motion follows] the ratio of the power of the motor to the resistance or power of the thing moved. This last opinion I consider true and the one held by both Aristotle and Averroes.
The first four lines were indented to make space for a capital "O", which apparently was never drawn (no trace of it is visible in the photocopy). There is another such "hole" further down the page.
Note the heavy use of abbreviations, such as the "backwards tail" for final "m", e.g. in motuum and eam on the first line; or the tilde in place of "n", as in omnis and ponit. Voynich hackers will probably note the 8-shaped "d"s. More generally, note the inconsistency in the use of abbreviations, and the use of different glyphs for the same letter in different contexts.
Finally, note the large number of repetitions and near-repetitions. This peculiarity is forced in part by the subject matter --- "ratio"s everywhere --- but sometimes also by the Latin grammar, as in the vel ... vel construction.
For another copy of these same lines, check the Cambridge manuscript sample.