44 



13 Diagram to explain Eclipses. 



14 Illustration of the Tides. 



15 Telescopic View of Mars. 



16 Telescopic View of Jupiter. 



17 Telescopic View of Saturn. 



18 Comet of 1811. 



19 Comparative Size of the Sun and 



Planets. 



20 Star Cluster of Resolvable Neb- 



ulae. 



PER SLIDE, $2.00. 



21 Bird's-eye View of Saturn and 



its ring system. 



22 Saturn, luminous points visible 



near the period of the disap- 

 pearance of the rings. 



23 Telescopic View of Saturn. 



24 Comparative size of Saturn and 



the Earth. 



25 Telescopic View of the Moon, a 



little before last quarter. 



26 Telescopic View of the Moon, 



just before the full. 



27 Scenery on the Moon. 



28 Mountains of the Moon ; view of 



the region southeast of Tycho. 



29 Comparative size /of Sun, the 



Earth and Moon^s Orbit. 



30 Eclipses and passages of the 



Satellites of Jupiter, seen from 

 the Earth. 



31 Parallax. 



32 Direct and retrograde motion of 



Mercury and Venus. 



33 The apparent size of the Sun 



seen from the principal Planet. 



34 Egyptian Zodiac. 



35 The Micrometer. 



36 Discovery of a small Planet by 



means of Ecliptic Charts. 



37 Ecliptic Chart. From M. Cha- 



cornac's " Star Atlas." 



38 Herschel's 40 feet Telescope. 



39 Measure of the distance of an 



inaccessible object. 



40 Deformation of the Sun's limb at 



sunset. 



41 Convexity of the Ocean. 



42 Solar Cyclone, May 5, 1857. 



(Secchi.) 



43 Donati's Comet. 



44 Spiral Nebulae in Virgo. (Rosso.) 



45 Nebulae in Andromeda. 



46 Elliptical annular nebula of the 



Lion. (Herschel.) 



47 Spiral Nebulae in Canes Venatici. 



(Rosse.) 



48 Lunar Crater. 



Class XXIX Geology. 



TWENTY SLIDES, PER SET, $30.00. 



1 The Geological Record. 



2 Ideal Section of the Earth's 



Crust. 



3 Thickness of the Earth's Crust. 



4 Section of a Volcano in action. 



5 Fingal's Cave. 



6 Grotto of Antiparos. 



7 Glacier Mt. Rose. 



8 Glacier Tables. 



9 Coral Island. 



10 Corals. 



11 Rain Drop Marks. 



12 Trilobites. 



13 Ammonites. 



14 Pterichthys Cocostes, Cephalas- 



pis. 



15 Fossil Fern impression of. 



16 A Thrust in a Coal Mine. 



17 Ichthyosaurus. 



18 Pterodactyl. 



19 Fossil Footmarks. 



20 The Mammoth Restored. 



PER SLIDE, $2.00. 



21 Skeleton of Megatherium. 



22 Sigillaria. 



23 Lepidodendron. 



24 Tracks (the Stone Books). 



25 Bone Cavern, Wirksworth, Eng. 



26 Skeleton of HydrarchosIIurlanii. 



27 Pentacrinites Briareus. 



28 Apiocrinites and Actinocrinites. 



29 Forest of the Coal Period. 



30 Dinornis Mantelii. 



31 Foraminifera (from Atlantie 



soundings). 



32 Lava Arch, Iceland. 



