II.  TECHNOLOGY.—­Improved Plaiting Machine.—­With engraving.

      Self-acting Shuttle Guard.—­1 figure.

      Ruler and Triangle for Hatching.

      The Distillation of Sea Water.—­1 figure.

      Aids to Correct Exposure on Photographic Plates.—­An
      interesting paper by W. Goodman.

      Isochromatic Photography.—­By Fred. E. Ives.—­2 figures.

      Distortion from Expansion of the Paper in Photography.

III.  Electricity, etc.—­On the Fritts Selenium Cells and
      Batteries.—­A paper read before the American Association
      by C.E.  Fritts.

      Electricity Applied to the Manufacture of Varnish.—­2 figures.

      Naglo Brothers’ Telephone System.—­3 figures.

      The Gerard Electric Lamp.—­1 figure.

      A New Reflecting Galvanometer.—­3 figures.

IV.  ART AND ARCHITECTURE.—­Groups of Statuary for the Pediment of the House of Parliament in Vienna.—­2 engravings.

      The Casino at Monte Carlo.—­An engraving.

V. PHYSICS.—­Determining the Density of the Earth.—­1 figure.

      Physics without Apparatus.—­The Porosity and Permeability of
      Bodies.—­A Hot Air Balloon.—­2 engravings.

VI.  NATURAL HISTORY.—­Winter and the Insects.—­An engraving.

      Silk Worm Eggs.—­With engraving.

VII.  HORTICULTURE.—­The Melleco.—­Ullucus tuberosa.—­With engraving.

VIII.  Physiology, medicine, etc.—­Histological Methods.—­Section
      cutting machines.—­Methods of preserving the
      tissues.—­Preservative media.—­Preparation for mounting
      tissues.—­1 figure.

      Life History of a New Septic Organism.

      Erythroxylon Coca as a Therapeutic Agent.—­By Dr. E.R.  Squibb.

* * * * *

NEW SPANISH ARTILLERY.

The Spanish Government is now engaged in supplying some of its principal fortifications with heavy guns of the most improved construction.  The defenses of Cadiz and Ceuta have been greatly strengthened in this respect.  The most recent additions are some very powerful Krupp guns for the fortress of Isabel II., at Mahon.

[Illustration:  New Krupp breech loading guns for Spanish fortifications.]

We give engravings from photographs, as presented in La Illustracion Espanola.  These guns are breech loaders, of steel, 301/2 centimeters caliber, or 12 inches, 49 tons weight.

[Illustration:  New Krupp breech loading guns for Spanish fortifications.]