V. MINERALOGY.—­Precious Stones of the United States.—­A review of Mr. G.F.  KUNZ’S recent report on this subject.

VI.  Miscellaneous.—­A Clinical Lesson at “La Salpetriere.”—­A
      portraiture picture by M. Andre Brouillet, of a clinic.—­2
      illustrations.

      Inauguration of the statue of Denis Papin.—­The statue to Papin
      erected in Paris by popular subscription.—­1 illustration.

      The Action of the Magnet in Hypnosis.—­The nullity of the action
      of the magnet disclosed.

      To Find the Day of the Week for any Year.—­A new method devised
      by Lewis Carroll.

VII.  Naval engineering.—­Some Recent High Speed Twin
      Screws.—­By E.A.  Linnington.—­An important paper on the subject
      of screw propulsion.—­6 illustrations.

      The Havre Maritime Exhibition.—­Notes on the recently opened
      exhibition of ships and naval appliances at Havre.—­1 illustration.

      The New German Corvette Greif.—­A recent addition to the German
      fleet illustrated and described.—­1 illustration.

      The Steamship Great Eastern.—­A plea for the mammoth
      steamer.—­Probabilities of her future usefulness.

      Twin Screw Torpedo Boat.—­The new sea-going vessel built by
      Yarrow & Co. for the Italian government.—­Her extraordinary
      speed.

VIII.  ORDNANCE.—­Our Coast Defenses.—­An interesting summary by Gen. H.L.  ABBOTT of our means for defending our coasts.

      The New Krupp Guns.—­The dimensions of the largest guns in
      the world, now in process of construction at Essen.—­2 illustrations.

IX.  PHYSICS.—­Colors of Thin Plates.—­Report of a recent lecture by Lord Rayleigh.

X. Technology.—­Recent Advances in Sewing Machines.—­By
      John W. Urquhart.—­A recent lecture before the Society of
      Arts of London, giving an exhaustive review of the subject.—­15
      illustrations.

* * * * *

THE HAVRE MARITIME EXHIBITION.

The Havre Maritime Exhibition opened on the 7th of May.

Will this exhibition awaken general interest, or will it prove a local affair simply?  This is a secret of the weeks that are to follow.

Should nothing chance to discourage the general interest that surrounds Havre, to dampen the enthusiasm of the public, or to act to the prejudice of the exhibitors, whose very evident desire is to show nothing but remarkable products in every line, the International Maritime Exhibition will prove a great success.

[Illustration:  The International marine exhibition at Havre.—­The principal entrance.]