8 



results, but that sulphate of ammonia proved even m6re efficacious, 

 especially in the production of foliage crops. Of the potash salts, 

 the sulphates gave better results than the muriates, while bone- 

 black had a marked effect in increasing the number of blossoms. 



The Meteorological. 

 Presitlent H. 11. Goodell, Director. 



Sir : — The work in the meteorological department the past year 

 has been a continuation of that begun the year preceding, together 

 with additional labor in certain special lines. Particular attention 

 has been given to the study of weather prognostics, climatic con- 

 ditions and signs of local weather changes. Special study also 

 has been made of solar and lunar halos and coronne, and their 

 appearance, as precursors of coming storms. A series of experi- 

 ments has been carried on for some months for the purpose of 

 ascertaining the effect of dynamical electricity on the growth and 

 development of vegetation, also the effect of incandescent electric 

 light on plant development, the results of which w^ill appear later 

 in the form of a bulletin. As atmospheric electricity is considered 

 of late a potent factor in the economy of nature, it was thought 

 proper to make it a careful study and undertake a series of 

 observations in this department of meteorology. Preparations, 

 therefore, have been made in this direction by placing an electro- 

 graph in the observatory. The following is a general description 

 of the instrument. 



The electrograph consists of a Thomson's quadrant electrometer, 

 registering ajj^^aratus and water-dripping apparatus. A jmrtial 

 description of the different parts will be found under their 

 appropriate headings. When in proper position, the electrometer 

 is enclosed in a glass case, the registering apparatus in a mahogau}^ 

 case, and the whole arrangement is mounted on a strong slate 

 slab. The instrument was constructed by Elliott Bros, of 

 London especially for this observatory, from drawings made by 

 Sir William Thomson, and is designed for observations in atmos- 

 pheric electricity. 



The Electrometer. — The quadrant electrometer (see Fig. 4) 

 has first a white Hint glass bell jar, surrounded and supported, 

 mouth up, by a metal casing. The outside of the jar is partially 

 covered with tin-foil, while the inside contains strong sulphuric 

 acid to the depth of about three inches. The acid serves a three- 

 fold purpose : (a) it keeps the air inside quite dry, thereby 

 insulating parts required to be so ; (6) it holds a charge of 



