TRANSACTIONS OF THE SECTIONS. 41 



On a New Method of making Maximum Self- Registering Thermometers. 

 By John Phillips, M.A., F.R.S., Reader in Geology in the JJniversity of Oxford. 



Thermometers constructed after this plan were first exhibited by Prof. Philfips, 

 accompanied by a description, at the Oxford Meeting of the Association in 1832. 

 In consequence of a careful examination by Mr. Welsh, of the principle on which 

 they were arranged, attention was again called to the subject. The principle of the 

 instrument is the employment of a certain portion of the column of mercury, detached 

 as a marker. The length of this is capable of a great range of adaptation, to suit 

 the objects of experiment ; when set to work, the instrument is independent of 

 change, by time or chemical action, and as delicate in operation and as free from 

 error as the best ordinary thermometer can be made. Mr. Phillips constructed 

 many twenty-five years since, some of which remain in excellent state to this day. 

 The length of the marker was varied at pleasure, by means of a second hollow ball 

 blown at the extremity opposite the ball containing mercury. The longer this marker 

 is left, the easier is its flow : at a certain small length, depending on the diameter of the 

 tube, it will remain without turning in any position, and requires strong shaking to 

 change its place. Mr. Welsh constructed some in a manner superior to that for- 

 merly employed by Prof. Phillips, and reported in very favourable terms on the 

 accuracy and permanency of the instrument. Thus encouraged, Mr. Casella had 

 undertaken to adapt the thermometer to diflferent purposes in meteorology and philo- 

 sophical research, but without changing in any degree the essential character of the 

 instrument. Among the examples on the table was one which was planned by Prof. 

 Phillips for special researches on limited sources, or areas, of heat, with small bulb, 

 fine bore, and short detached marking column. Thus made, the thermometer may be 

 used in any position, vertical, inclined, or horizontal, and the short detac/ied marking 

 column will retain its place with such firmness that instruments may be carried far, 

 or even agitated much, without losing the registration. 



Observations ivith the Aneroid M^tallique and Thermometer, during a Tour 

 through Palestine, and along the shores of the Dead Sea, October and 

 November 1855. By Henry Poole. 

 During a recent tour through Palestine,! carried an Aneroid Metallique, and though 



I would not presume to say that the results of observations made with it are quite 

 correct, yet as the readings in many instances are close approximations to the cal- 

 culations of Lynch and other travellers, I wish to draw attention to that instrument 

 as affording an easy mode of obtaining approximate levellings of heights in unsur- 

 veyed countries. It is light, and can be easily carried by a strap over the shoulder. 

 From the rackwork being visible, a readjustment can easily be made when required 

 upon ascending high mountains. 



A table of corrections is, however, required, and which I found must be additive 

 with an increase of temperature (being the reverse of mercurial barometers and 

 vacuum aneroids), as indicated by the variation in the readings at different tempera- 

 tures at the same localities, as recorded in the accompanying Table. 



In Dent's tables, 85 feet are calculated for the difference of each tenth of an 

 inch of the barometer; this, multiplied by 39'37 inches, equal to a metre, gives 33'46 

 feet, or 33^ feet in common practice, as the multiple of each division in the Aneroid 

 Metallique. In practice I found it very nearly correct; for instance, there are forty- 

 seven steps with a 6-inch rise going down into the Tomb of the Virgin Mary in the 

 Valley of Jehosophat equals 23*5 feet, and by aneroid I read a difference of 7 milli- 

 metres X by 33"5=23"45 feet ; again, the minaret of the Church of Ascension on 

 the top of the Mount of Olives measured 36'5 feet, — by aneroid the difference was 



II millims. X 33"5=:36'85 feet. If the aneroid were mounted with a vernier scale, 

 the observations could be more closely read off. I particularly mention these com- 

 parisons of the aneroid with actual measurements, as they gave me confidence in it 

 at the time, and also because I found on my return to London that I had arrived 

 very nearly to the same results as Lieut. Lynch up to 2000 feet above the level of 

 the Mediterranean Sea; and also in the depression of the Dead Sea, 1313"5 feet by 

 aneroid, while Lynch made it 1316'7 feet by level, and Capt. Symonds calls it 1312 

 feet. There is also a variation in the line of the Dead Sea level at different seasons 



