_e._ Machines; Lord Rosse; Mr. Lassell; spiral stroke machine; its construction and use; the foot-power; method of local corrections; its advantages and disadvantages; machine for local corrections; description and use 19 4. _Eyepieces, plane mirrors, and test objects_ 26 §2. THE TELESCOPE MOUNTING 27 Stationary eyepiece; method of counterpoising 27 _a._ The tube; the mirror support; air sac; currents in the tube 28 _b._ The supporting frame 31 §3. THE CLOCK MOVEMENT 33 _a._ The sliding plateholder; the frictionless slide 33 _b._ The clepsydra; the sand-clock 36 _c._ The sun camera 40 §4. THE OBSERVATORY 41 _a._ The building 41 _b._ The dome; its peculiarities 44 _c._ The observer’s chair 45 §5. THE PHOTOGRAPHIC LABORATORY 46 _a._ Description of the apartment 46 _b._ Photographic processes; washed plates; difficulties of celestial photography 47 §6. THE PHOTOGRAPHIC ENLARGER 51 _a._ Low powers; use of a concave mirror, its novelty and advantages; of the making of reverses 51 _b._ High powers; microscopic photography 54 AN ACCOUNT OF THE CONSTRUCTION AND USE OF A SILVERED GLASS TELESCOPE. The construction of a reflecting telescope capable of showing every celestial object now known, is not a very difficult task. It demands principally perseverance and careful observation of minutiæ. The cost of materials is but trifling compared with the result obtained, and I can see no reason why silvered glass instruments should not come into general use among amateurs. The future hopes of Astronomy lie in the multitude of observers, and in the concentration of the action of many minds. If what is written here should aid in the advance of that noble study, I shall feel amply repaid for my labor.