Extracts.
Notwithstanding the numerous experiments made since the seventeenth century upon the flow of liquid veins through orifices, there are important matters connected with this phenomenon which still remain undetermined, or so imperfectly known as to give rise to most inexact hypotheses.
Until now we have had no experimental results respecting the pressures exerted in the interior of the vein, or upon the velocities of the separate filaments.
It was therefore highly desirable that delicate observations upon a large scale should be undertaken for the measurement of the pressures and velocities within the issuing vein under considerable heads and with both vertical and horizontal orifices of diverse forms. M. Bazin's memoir contains an account of a large number of just such observations, made at Dijon since 1890, and concluded within the last few months.
The memoir contains an elaborate study of the flow through a vertical rectangular orifice, of the same width as the reservoir itself, and furnished externally with two flat cheek-pieces for preventing the lateral dilation of the vein. These are, so far as we know, the first precise observations made in such a case, the most important of all from a theoretical point of view, since it is the most elementary, and that to which mathematical analysis can be the most completely applied.
We see, then, that the memoir of M. Bazin realizes in many respects a very marked advance in our knowledge of the important and difficult question of the liquid vein. Your committee has therefore unanimously approved the memoir, and asks of you its insertion in the Recueil des Savants etrangers. In this publication have already appeared, during the present century, the memorable experiments of Poncelet and Lesbros upon the flow through vertical orifices; of Poiseuille upon the flow through capillary tubes; of Darcy, upon the uniform flow in larger pipes; of Darcy and of M. Bazin himself, upon the flow in open channels: a most valuable collection of original documents of the first order in the study of hydrodynamics, and one which will in no wise disparage the new work of M. Bazin.
The conclusions of the report were put to vote and adopted.