Show MEASURING SEA LEVEL work of student at mac ahlm fie the marking of the average height of the ocean ascertaining that 18 the mean sea level might seem to be very elpidio until the experiment had been aled b ne might supporter example that it could be observed on the side 0 a aba butted jutted ou into deep water or oa ft gradually sloping beach or by means ofa pole planted in the water a short distance oft shore it would soon bo found however that owing to the dally changes in the tides fluctuations 0 the waves such a mark would have to be moved up and down from day to day and the mean aea level would etall elude determination there are several methods of obtaining accurate tide measurements however from which the mean sea level may be computed ono of the simplest being that recently employed at ma celaa me by a party from a summer school of the massachusetts institute of technology inq actual measurements were made at howards bay about 11 miles from the town of ma ahlas one of the mean aea level stations also of the united states coast and geodetic survey by jneane of a glass tube closed at ohp bottom except for a small opening not over one awen bieth of an inch in diameter at which the water might enter aa it rose the air escaping at another opening at the top of the tube the water enters eo small an opening very slow lya wave docs not flow into it only the steadily rising tide nor does the inside water have time to flow out through such an opening during the depression between two waves the water which the tube contains constantly rises and falls therefore with the tide and la little influenced fluen ced by tho wave action since the of the aldo at howards bay la 10 feet the tube of the gauge was built up 18 feet in sections of three foet each and attached to a beam which waa firmly braced to withstand a at low water it was possible for the institute students to approach near enough to read ta record easily but at high water it was necessary to make the reading through a telescope this gauge gave th measure mant of extreme high and extreme low tide from day to day but in the course of a month or from ono full to another a period during which the sun and moon proceed through practically a complete cycle in ther influence on the ebb and flow of the jeaan average could be obtained from which bythe by the use of published tide tables the mean cea level could be accurately determined the recent italian census records the fact that there are persons in italy over a mcgra old among them arc sixteen honki and nuns A insect has appeared in california in time to devour the ggs counties count les red spiders tant injure jhc sroy y x |