December 6, 1912] 



SCIENCE 



797 



The observatory is very favorably situated 

 for the study of mountain and desert meteorol- 

 ogy, the relation of topography to thh occur- 

 rence of frost, and the influence of mountains 

 and forests upon the conservation of snow. 

 Most of the instruments and methods employed 

 in the v^ork of the observatory have been de- 

 vised by its staff. 



In the study of mountain meteorology, the 

 observatory has the advantage of occupying a 

 virgin field, and thus being placed in a posi- 

 tion to supplement the work done at Mount 

 Eoyal by McGill Observatory, in the Appa- 

 lachians by the Mount Washington, Blue Hill 

 and Mount Weather observatories, in the 

 Rocky Mountains at Pikes Peak, and in the 

 Coast Range at Mount Tamalpais. Mount 

 Rose Observatory is unlike its predecessors in 

 that no observer is maintained continuously 

 on the summit, and most of the instruments 

 in use have been constructed to work without 

 attention for long periods of time. 



After much experimenting there has been 

 devised a meteorograph that is impervious to 

 the wild storms that rage in winter on moun- 

 tain summits, and a shelter has been con- 

 structed for it that clears itself of accumu- 

 lated snow. Six elements are recorded, viz. : 

 pressure, temperature, direction and velocity 

 of the wind, humidity and sunshine. The 

 records are made upon a band of metric cross- 

 section paper 270 mm. wide, which moves 

 2.5 mm. an hour or 1.8 meters a month. The 

 recording mechanisms are adjusted to the 

 ruling of the paper so that one millimeter 

 equals one degree of temperature, two per cent, 

 relative humidity, and one millimeter of at- 

 mospheric pressure. The meteorograph is 

 actuated by springs placed within a motor 

 drum. Two auxiliary drums serve to hold and 

 receive the paper as it passes over the motor 

 drum against which the recording pens rest. 

 This instrument will run for at least two 

 months with one winding of the clock. The 

 resetting of the meteorograph is readily ac- 

 complished by disconnecting it from the 

 shelter and removing it to the observatory 

 building. 



Some defects that occasionally cause fail- 



ure to obtain satisfactory records have been 

 partially corrected in the following manner: 

 To prevent slipping of the record sheet, a 

 double series of tiny needle points has been 

 fitted into the motor drum with v-edged pres- 

 sure wheels running astride of them to force 

 the sheet close to the drum. To detect possible 

 inaccuracy in the motor clock, a standard 

 pendulum clock actuated by weights has been 

 installed in the observatory building and con- 

 nected by electric cable with a pen in the 

 meteorograph to record the twelve o'clock 

 hours each day. Excessive vibration has been 

 eliminated in the shelter by the use of heavy 

 braces and rock on the sills. 



Mechanical registration is employed in all 

 elements except sunshine, and the performance 

 of electrical devices tried thus far has been 

 so unsatisfactory that probably a mechanical 

 sunshine recorder will eventually replace the 

 electrical one. Dry batteries have been made 

 worthless by freezing, and the efficiency of wet 

 batteries is so reduced in cold weather that it 

 seems improbable that any system depending 

 on electricity will be successful. 



The great problem is the prevention of the 

 formation of fins of ice and frost upon the 

 instruments. The sunshine recorder has been 

 safeguarded by a heavy bell- jar. The tail of 

 the anemograph vane has been made of wood 

 and the arrow so shortened that the vane will 

 swing into the eye of the wind irrespective of 

 ice accumulations on the arrow. The masts 

 have been enlarged in size and made seK-sus- 

 taining without guy rods, which invite the 

 formation of festoons of heavy ice with con- 

 sequent wrecking of the masts. The only 

 serious problem of equipment still unsolved is 

 the protection of the cups of the anemometer 

 from ice. This can be accomplished in part 

 by removing the portion of the supporting 

 arms that pass through the cups and thus ex- 

 pedite the dropping of the accumulated slugs 

 when the cups are warmed by the returning 

 sun. However, there may be some material, 

 such as vulcanized rubber or papier mache, of 

 which cups can be made, which will be less at- 

 tractive to frost and ice than the metals used 

 at present. The wind record has usually been 



