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6 Oct 11th 1839 visited today with Mr. S Alexander Mount Rose where Mr. Hasler has one of the stations for the trigonometrical survey of the coast of the United states. We were much pleased with operation of the heleotrope, the instrument for throwing a beam of light to answer as a signal. It consists of a piece of looking glass about 2 inches long by one wide attached to the end of a telescope in such a position that when the telescope is directed to the distant object, a beam of light is thrown on the same object. [[image]] To understand the most simple arrangement of this heliotrope, let [[underline]]a[[/underline]] be a mirror, [[underline]]c[[/underline]] a telescope with two screens [[underline]] d e [[/underline]] with a hole in each so that the centers of these will be in the same line parallel with the axes of the telescope, now let the telescope be directed to the distant object and at the same time the mirror so turned that a ray of light from the sun shall peep through each hole in the screen of the telescope then it is evident that the beam will keep parallel to the axis of the glass and be thrown on the object to which the instrument is pointed. From the station at Mount Rose, 8 stations are visible, and from 6 or 7 of these, light was streaming from as many heleotropes like so many stars of the first magnitude. They were mostly distinctly visible by the naked eye, [[end page]] [[start page]] 7 Oct. 12th although at the distance of 17 miles the [[underline]]nearest[[/underline]] Oct 12th [[image]] Arranged a Leyden jar within a coil sent current from little machine through coil or rather helix (no. 1) placed together near the [[Rush?]] of jar, but could discover no effect. Arranged the small decomposing apparatus belonging to the magneto-electrical machine, so as to produce decomposition in two small tubes containing acidulated water, found the current in the final arrangement + in the 2nd arrangement which gave a tertiary current, the current was [[line drawn across page]] [[image]] sent ^[[secondary]] shocks from the small machine (Page's) through a glass tube containing nitrate of Zinc. [[Tourmalines]] placed on the side so as to observe if any polarization of light was produced at the instant the discharge took place- [[underlined]] no effect was observed [[/underlined]]. The tube was covered entirely with tin foil and two holes made in this to transmit the light *See bottom of page [[line drawn across page]] [[image of syphon]] Made a short syphon of lead, put the longer leg into a cup of mercury put it away to determine if the mercury will be delivered at the shorter leg. Inspected the above arrangement on Monday the 14th, but found no indication of mercury at the shorter end. Inspected the same on the 15th, found that the mercury had reached the lower surface of the section of the shorter leg, but there was no apparent [[tendancy?]] to [[peep?]] out, it stood like a dew on the lead - Inspected this again on the 28th with [[word]] the same, lead saturated nearly throughout exp perhaps a small cylinder around the axis. *Made same exp with oil of aniseed no result
