Sun Viewing and Drawing. 429 



stopping the engines. Should the vessel leak, the water may- 

 be obtained from its hold instead of from the sea ; and thus, 

 by the very act of propulsion, the vessel will be kept afloat. 

 Satisfactory velocities have been obtained by the "Water- 

 witch;" but the real question is that of economy, and regarding 

 this no satisfactory data has yet been given by the experiments 

 hitherto made. The only novelty in either the American 

 vessel or the " Waterwitch n consists in ingenious combina- 

 tion of details which have long been known. The position of 

 the exit tubes in the American experiment is evidently bad. 

 They are exposed to injury, and the resisting medium is far 

 inferior in efficiency to what it would be were they at some 

 depth below the surface of the water. 



Oars have been in a great degree superseded by sails, sails 

 by paddle wheels, paddle wheels by the screw, and now the 

 screw appears not unlikely to be set aside by a contrivance 

 founded on a principle which is perhaps as old as most of them. 

 How many valuable principles are allowed to remain for ages 

 without practical application? The most important triumphs of 

 science, those which have had the most effective influence on 

 progress, are but developments of facts and principles that 

 were Ions: known. 



SUN VIEWING AND DRAWING. 



A READY METHOD FOR OBSERVING AND DEPICTING- SOLAR 

 PHENOMENA, BY MEANS OF PROJECTING- THE SUN'S IMAGE 

 UPON A SCREEN. 



BY THE EEV. FEED. HOWLETT, M.A., F.E.A.S. 



(With a Tinted Plate.) 



Seldom has the writer met with an instance wherein very 

 simple means and cheap appliances have, at least in a certain 

 special line of astronomical observation, commanded better 

 results, than the one which it is proposed to make the subject 

 of the following paper. With respect, then, to the investi- 

 gation of the sun it is encouraging to amateurs to know how 

 much good work may be done by the aid of only a very 

 moderate-sized telescope, in combination with a few simple and 

 inexpensive accessories presently to be described. 



Anyone possessing a good achromatic of not more than 

 three inches aperture, who has a little dexterity with his pencil, 

 and a little time at his disposal (all the better if it be at a 

 somewhat early hour of the morning) shall be made acquainted 

 with an easy method whereby he may deliberately and satis- 

 factorily view, measure, and (if skill suffice) delineate most of 



