NA TURE 



[September i, 1898 



depending portion of the rod, and when the galvanometer spot 

 showed that the temperature gradient along the rod had become 

 steady, the galvanometer was adjusted to false zero ; the flame 

 was then removed, and after waiting a second or so until the 

 spot was beginning to move in the cooling direction, a vessel of 

 water was brought up over the' hot end, the galvanometer spot 

 at once moved nearly across the scale in a direction indicating 

 a rise in temperature. Further experiments seemed to show 

 that this heating effect was greater when the temperature of the 

 heated end was sufficiently high to produce the spheroidal 

 state ; when this was not the case, the movement of the spot in 

 the cooling direction was decreased or altogether stopped, but 

 no increase in temperature was indicated. With the copper 

 rod arranged as described, no perceptible movement of the spot 

 in the heating direction took place until about thirty seconds 

 after the application of the bunsen flame. An attempt was 

 made to see if an opposite effect could be obtained when a 

 heated metal sleeve was slid over the 4" portion, but nothing 

 definite was observed. In connection with the apparently in- 

 stantaneous manifestation of a rise of temperature at the cooler 

 end of the bar following the cooling of the hotter end, other ex- 

 periments suggested themselves. For although the experiments 

 described were oitly preliminary and somewhat rough and ready, 

 yet I think it was established by them that the velocity of trans- 

 mission of the effect is very much higher than that of heat by 

 ordinary conduction or convection. The objects of the further 

 experiments were to find out, if possible, to what the effect is due 

 and what is its mode of propagation. In order to ascertain if 

 the effect could be obtained in liquids, a piece of thin weldless 

 steel tube, closed at one end and about 9 inches long, was filled 

 with mercury and the bulb of a thermometer was just submerged 

 beneath the mercury. On experimenting in the manner already 

 described a very slight heating effect was observed, which might 

 nave been due to a sudden cooling of the glass bulb, and no 

 definite results were obtained. Here the writer had to drop the 

 investigation. 



When a heated sphere is plunged into water, a rise of tem- 

 perature in the inner portion might take place owing to the 

 work done on it by the cooled and contracting envelope, but in 

 the case of the copper rod this does not seem a sufficient 

 explanation. 



If, as I hope, some of your readers undertake to investigate 

 this very interesting phenomenon, I would be pleased, if it be 

 of any service, to give them particulars of the experiments I 

 had proposed carrying out, but for which, unfortunately, I have 

 neither time nor opportunity. Albert T. Bartlett. 



Old Charlton, S.E., August 22. 



The Use of Digraphs. 



If ail writers, or, better still, all printers followed the rule of 

 Mr. Horace Hart, and never permitted the use of se and ce, 

 but always spelled them out ae and oe, many happy results 

 would ensue. Authors would cease to confuse editors and 

 printers with undecipherable attempts to represent a diphthong ; 

 5 per cent, of the misprints that have to be corrected in 

 technical biological papers would disappear ; zoological names, 

 if no others, might at last be written correctly, and the student 

 no longer confused with coelatus when caelaHis was meant, 

 and so forth. There need be no confusion with those rare 

 words in which the vowels are distinct, since the custom of 

 printing "aerated," " oology," and the like already prevails. 

 If the only evil in sight is that Mr. Montagu Browne will feel 

 impelled to the exceedingly unnecessary task of rewriting his 

 museum labels, by all means let us entreat the printers to 

 reform. , F. A. Bather. 



Natural History Museum, 



THE APPROACHING MEETING OF THE 

 BRITISH ASSOCIATION AT BRISTOL. 



The Excursions. 

 T N a district so rich in geological and antiquarian, 

 -*■ as well as industrial, interest as that of which 

 Bristol forms the centre, it is to be expected that the 

 excursions will form an attractive feature of the ap- 

 proaching meeting. A brief synopsis will serve to 



NO. 1505, VOL. 58] 



indicate some of the salient points of the varied: 

 programme. 



Taking first the Saturday excursions, that (i) to Bath 

 will occupy the whole day and will include the Roman 

 Baths and Remains, the Moore Museum (geological), 

 the valuable collection of local antiquities at the Insti- 

 tution, and the fine Abbey Church. Geologists will 

 have an opportunity of visiting sections of White Lias 

 and Rhaetic, under the guidance of the Rev. H. H. 

 Winwood. In the afternoon the party will drive to 

 Claverton Down and Manor, returning by Widcombe 

 and Beechen Cliff, where a bird's-eye view of Bath is 

 obtained. Another whole-day excursion (2) includes 

 the Severn Tunnel, with its pumping apparatus of 

 fourteen engines on the Cornish type capable of lifting 

 eighty million gallons per diem ; Chepstow Castle, which 

 still retains some of the original eleventh century masonry 

 and an Early English chapel ; the Chepstow railway 

 bridge, in which the tubular and suspension principles 

 are combined, and the Severn Bridge with its swing- 

 bridge weighing about 400 tons. A half-day excursion 

 (3) is arranged to Aust Cliff, which presents a section- 

 of great interest to geologists. This will be examined 

 with Mr. H. Pentecost of Clifton College as guide. It is 

 hoped that enough of the Rhaetic bone-bed, with its rich 

 store of saurian and fish remains (mcluding the teeth of 

 Ceratodus) may be brought down to the beach to give 

 the geologists of the party an opportunity of securing good 

 specimens. This excursion also includes a visit to Over 

 Court and Knowle Park. Another half-day excursion (4) 

 is to Stanton Drew with its striking megalithic remains, 

 including three stone circles, two "avenues," a dolmen (if 

 such it be), and several outlying stones included in the 

 scheme of construction. Prof Lloyd Morgan will here 

 be guide. The drive also includes Sutton Court, the 

 residence of Sir Edward Strachey, and, if the weather be 

 clear, Dundry Hill, whence a fine and extensive view^ 

 comprising scenic features of formations from the Old 

 Red Sandstone to the Chalk, is obtained. Those who 

 are interested in docks, lairage, chill-rooiTis,and granaries, 

 may devote the afternoon to Avonmouth (5) and see, 

 under the guidance of Messrs. Girdlestone and McCurrich,. 

 the floating pontoon dock and cold storage installation. 

 Those for whom architecture has stronger attractions- 

 will perhaps select either Raglan Castle and Tintern. 

 Abbey (6), to which the whole day will be devoted, or 

 Bradford-on-Avon (7), with its unique and perfectr 

 little Saxon Church of St. Lawrence, its quaint old' 

 Town Bridge, its fourteenth century Tithe Barn, and! 

 its residential houses, including that in which Dr.. 

 John Beddoe, F.R.S., now resides. Those, again,, 

 who seek an impressive lesson in physical geology - 

 and the origin of scenery, may. drive from Yatton to- 

 Cheddar (8), through the Vale of Wrington, and Bur- 

 rington Combe, over the arched dome of Mendip, and 

 beneath the splendid inural bastions of Carboniferous 

 Liinestone in the Cheddar gorge, visiting the interesting 

 stalactitic caves near the little village of Cheddar. While 

 those who wish to see one of the best examples of an 

 ancient dry-walled camp, with a number of curious pits, 

 probably for storage of grain, in which skeletons with 

 ugly gaps in their dolicho-cephalic skulls have been 

 found, may take the afternoon excursion to Weston- 

 super-Mare and Worlebury. 



On Thursday, as on Saturday, there is a wide range of 

 choice. One party will have an opportunity of driving , 

 to the Barrow reservoirs and Chelvey pumping statior> 

 of the Bristol Water Works (10). The supply of water 

 comes from springs on the Mendip Hills, about sixteen 

 miles from Bristol, from others at Barrow Gurney, and 

 wells at Chelvey, near Nailsea. The storage reservoirs 

 at Barrow Gurney have a water-area of about 130 acres,, 

 and extensive filter-beds. At Chelvey there are pump-', 

 ing engines of the rotary beam type, with single andf 



