Contains an important portion of Boussinesq's papers: such as the printed works of Adhm̌ar Barr,̌ Count of Saint-Venant (1797-1886) with annotations by Boussinesq; also (I-V): I. (4221) Biographical notes by Ed. Phillips and J. Boussinesq; 'Notes on scientific works' (1843, 1858, 1864, and 1868); printed and lithographed opuscules (1843-1863). 270 x 220 mm. (canvas covered); II. (4222) Opuscules (1864-1885); 'Reports on the works... of Mr. Boussinesq (1880 and 1886); 'School of Civil Engineering. Lessons in applied mechanics' (1837-1838). 270 x 220 mm. (canvas covered). III. (4223) Printed works in-octavo, among which one can find the biography of Count Pierre du Buat by Saint-Venant (1866 and 1884) and the 'Lessons of analytic mechanics' by Father Franȯis Moigno, on proofs corrected by the author (1867-1868). 220 x 140 mm. (canvas covered). IV. (4224) Posthumous or manuscript works (1834-1889), preceded by a biogaphy by J. de Prm̌illy (1887). 290 x 220 mm. (canvas covered). V. (4225) Papers and note from various scientists. 1. 'Curving shape taken by the primitively straight sections of a rectangular piece solicited towards flexion and transversal sliding,' by Gabriel Lam ̌(1874); followed by Saint-Venant's conclusions (1878). 141 sheets. 2. Letter from Rudolph Clausius and translation of his paper on the 'formulas in usage up to now for the balance and the movement of solid elastic bodies,' (1862). 15 sheets. 3. Translation by Father Franȯis Moigno of a memoir of Herman von Helmholtz on vortex motion (1867), letter from the latter, and a note on the discontinuous movement of fluids (1868). 38 sheets. 4. Papers by Louis Cuvinot on 'Water volume of the Seine at Mantes', by John MacCowan and Auguste Boulanger on 'the solitary wave' (1891), and by Edgar Baticle on 'The calculation of support walls' (1913-1914). 37 sheets. 5. Boussinesq's notes, especially on 'the conciliation of moral freedom with scientific determinism' intended for the 'Reports of the Academy of Sciences (1877-1878); Boussinesq's petitions to the Minister of Public Education (1874-1891). 21 sheets.