C. Baillairgé, Esq

The Stereometrical Tableau should be in use in every school where Mensuration is taught within the Dominion. 26 Dec. 1871. J. O'Farrell.

I havejcompared, in the case of several solids, the results obtaiued by your mode of computation with those resulting froni the ordinary and more lengthy processes, and congratulate you sincerely on your enunciation of a formula so brief and simple in its character and so précise and satisfactory in its results.

Québec, 27 Dec. 1871. E. T. Fletcher,

Inspecter of Survcys Dept. Crown Lands.