1751. The Gregorian or New Stile the most exact. Pope Gregory XIII. finding the Julian account to be erroneous, refolved upon a reformation of it, which he finished in the year 1582, and which from him is called the Gregorian account, or New Stile. The pope in his reformation look- A ed no further back than the time of the council of Nice, which was held in the year 325, and finding the vernal equinox was then on the 21ft of March, he ordered ten days of the year 1582 to be omitted, which was done by calling the 5th of October (his birth-day) the 15th; fo that the next vernal equinox, which otherwise would have been on the 11th, fell on the zift of March. And to prevent errors of the like nature for the future, he ordered the fubtracting three days from every re. volution of 400 years, which was to be done by omitting the 29th day of February at the end of three centuries fucceffively, and at the end of the fourth century to retain it. B 117 by which you may easily observe, that in process of time, if our Stile is not rectified, the times of the seafons of the year will be very much changed, and we shall err most egregioufly in the fixt as well as moveable feafts; as indeed the error is too confiderable already to be disregarded. Pope Gregory, in the year 1582, obferving this material difference, in order to restore the vernal equinox to the 21ft of March, as fuppofed at the Nicene Council, rejected tea days (at which time the equinox was fo much anticipated) in the Julian year, and made the 11th of March (the day whereon the vernal equinox then happened) to be the zift; and, in order to fix it there, ordered C every 100dth year, which should be biffextile, to be but a common year, for three centuries fucceffively, and the fourth century to be bissextile and fo on continually. This is the reason, that before the 29th of February, 1700, the diffe- D rence between the New and Old Stile was only 10; whereas fince that time it has been 11 days. As the following Account is fomewhat more minute and circumftantial, we have thought fit likewife to infert it. The kalendar, as rectified by pope Gregory XIII. is much the best and correcteft for regulating the moveable feats, and will continue agreeable to the folar year for a long feries of time, with but very little variati on. E F Confider how much the Julian account has erred in time fince the Nicene council, in the year of Christ 325. The fun then entered the vernal equinox, March 20, (tho' the council of Nice fixed it on March 21.) The fan entered the vernal equi- G nox this prefent year, March 9. in the afternoon, which is eleven days' between the folar and civil Julianyear, in the space of 1426 years; According to this inftitution there will not be above one hour 54 minutes difference between the civil and folar year in 400 years, which will not amount to an entire day in 50 centuries; which is near as much time as the vulgar account of the creation: Therefore, the moveable and fixt feafts being once fet upon good footing, they will continue fo for 60,000 years, without differing from the original inftitution, any more than the Julian account differs at this prefent time. (See more of this in our Mag. for 1747, p. 162.) From the PHILOSOPHICAL TRANS- A Defcription of an extraordinary An Extraordinary RAINBOW. bow, which appeared to take in a large portion of the heavens; but had nothing remarkable, and vanished by degrees. Continuing my walk, about 20 minutes after the difappearing of the first rainbow, a rainy cloud A croffed me, moving gently with the wind, which exhibited to me a more perfect and distinct rainbow than I had ever before feen; wherein I could plainly diftinguish all the fecondary orders of colours taken notice of by the late Dr. Langwith, in his letter to Dr. B Jurin, published in the Philofophical Tranfactions, No. 375; that is to fay, within the purple of the common rainbow, there were arches of the following colours; 1. Yellowish green, darker green, purple. 2. Green, purple. 3. Green purple. C This innermoft arch Dr. Lang with calls fain: vanishing purple, and I likewife found, that it iometimes appeared and difappeared alternately; but during about two minutes it feemed to me to be as permanent as any of the other colours. March non, I was surprised, that the diameter of the bow appeared to me very fmall, compared with that I had feen a little before. The occafion of this, I think, muft have been, that the legs of the first-mentioned bow appeared to me to terminate at diftant places: Whereas in the latter appearance I could plainly fee both ends of the inner and outer bows terminate in the neighbouring fields, at a very small distance from each other: Hence, and from my being involved in the fhower which occafioned this rainbow, I conclude it was very near me; which might be one caufe of the great vividness of its colours, and of my diftinguishing the inner arches. But whether this was the only cause of thofe appearances, or whether they might not be owing to fome particular difpofition of the atmosphere at that time, I much question: As well becaufe I have often feen rainbows, which have been very near me, and opposed to a bright fun, wherein I D could not difcern these inner orders of colours, as that I have heard from. fome intelligent perfons, that foine very bright rainbows were feen foon after the folar eclipfe which happened on July 14, 1748; particularly, that an unusually vivid and diftinct rainbow was obferv'd at Twickenham three or four days after that eclipfe; which agrees with the day on which I faw the above mentioned appearance. I ftood ftill, and looked attentively at this appearance, during the whole time of its continuance, which was near eight minutes, and could for the greateft part of that time difcern all the above-mentioned colours, except the innermoft purple, E in the upper parts of the bow; but could not diftinguith any of them in thofe parts of it which were near the horizon, tho' they were extremely vivid, as was likewife the outer bow, in which the colours appeared as bright, tho' not fo well F defined, as in moft inner rainbows I had seen. As I had read Dr. Langwith's letter a fhort time before I faw this beautiful appearance, and as I compared his account with what I had feen, the fame evening, and again the next morning, I can the better be assured of the exact agreement of our obfervations. On my first feeing this phænome G Extract of a Letter from Mr. W. Arderon, F. R. S. to Mr. H. Baker, F. R. S. giving an Account of the prefent Condition of the Roman Camp at Caftor in Norfolk. HE town of Caftor is at preTHE fent in a very low condition, containing no more than between 20 and 30 fmall cottages. It flands about 4 miles S. W. of Norwich. and by tradition, and fome learned authors See London Magazine for 1748, p. 331. . 1751 An Account of a Roman CAMP. at this day, (excepting the camp) hot the leaft trace or footftep of any thing remarkable is left remaining. A B 119 to difcover how long before, the fea had paffed this height. I have been pretty exact in examining the fituation of this camp, imagining the two fides had pointed due E. and W, and the two ends N. and S. But I find they differ from it The camp itfelf lies near a fur- full 10 degrees, after allowing for the long S. W. from Caftor, and leads variation of the needle: Whence it you by a gentle descent down to the is plain, the meridian of the place little river Wentfum, (by fome cal- must have altered better than hali a led Taus, or Tefe) which fwiftly degree each century to the weftward, glides clofe to the end thereof, and, provided the fituation of the camp no doubt, at the first forming of the was placed due N. and S. when it camp was defigned to be part of the was firit formed. But, poffibly, the fortification on that fide, as well as Romans might not be exact as to the to fupply the army with water, and points of the compass, or perhaps to bring up fuch things as they wanted this variation was at firft difpenfed from the fea, if fo be their commu- with, to accommodate the camp to nication by land fhould at any time the natural declivity of the ground. be impended. What confirms me C Thefe difficulties, however, may betin this opinion, is a large ftaple and ter be cleared up, if fome ingenious ring of iron, which I myself have gentlemen would take the trouble to feen on the fide of the tower that examine fome other Roman camps ftands near the river; tho' now I in different parts of this kingdom, find that curious monument of an- to discover whether the Romans paid tiquity is taken away. However, a ftrict regard to the difpofing of on my fuppofition, this river muft D their camps with their fides to the have been much larger at that time four cardinal points of the compafs; than it is at prefent, or it could have which, I think, it will nearly amount been of little ufe for water carriage. to a demonftration that they did, if they are found to agree with this camp in its variation from 'due N. and S. We are told by tradition, as well as by fome learned authors, that the fea came up to this camp; and indeed every intelligent obferver muft confefs, that the marine bodies found in every part of Norfolk, on the highest hills, as well as in the loweft pits and valleys, are indubitable proofs, that at fome time or other the fea must have covered this whole County: But then we may be af fured, by the present condition of this camp, that the fea hath not exceeded the level of it fince it hath been in being, which, if we credit feveral of our antient hiftorians, it was upwards of 1700 years ago. It may therefore ferve to prove, that the fea fince that time has not exceeded these bounds, and that the foffils dug up above this level are more antient than it, tho' we have no proper data E The figure of the camp is not a fquare (as it is defcribed by most authors) but a parallelogram, whofe two longeft fides are each 440 yards, and its ends, or two fhorter fides, 360 each, Thefe are its dimenfions withoutfide the rampart and ditch; but withFinfidethelength is 392 yards, and the breadth 264. I measured the breadth of the foffe and rampart, which I found in fome places, where it remains molt perfect, to be 48 yards, tho' in others not above 30. And according to my computation, the whole ground G taken up, including the ditch and rampart, is 32 acres, 2 rood, and 36 pole; or the area within the ditch and rampart, 21 acres, I rood, 21 pole, A: 120 Roman Bricks, and their Manner of Building. Building. March high as the old ruins now remain ftanding.. At about 3 or 4 furlongs N. W. of the camp rifes a ridge of hills, appearing fomething like a fecond The mortar is found extremely rampart, and defcending gradually hard at this day: It is a compofition to the camp. Thefe hills add greatly of lime, fand, and afhes, and fo to the profpect, and tuft have been compact, that I could by no means no little advantage to the fafety of the A break a piece of it of an inch diaplace, as a conftant watch might be kept thereon to prevent any furprise; nor could an enemy advance nearer than the fummit of thefe hills, withput being expofed to the view of the whole camp. Three fides only of this camp B have been fortified with a rampart, whose upper part was faced with a thick and ftrong wall made of lime and flints, of which wall there are fill remains in feveral places of the rampart, befides a very deep ditch, that feems to have been moft confi- C derable on the E. and S. fides. The wall on the N. Side appears to have been built at two different times; that is, it feems to have been raised higher than it was built at firft, at fome diftance of time afterwards; for a parting may be obferved at a certain height, running from end to end. meter from the base of one of the towers at the eaft gate, but on ftriking it with a fharp flint it flew off in duft. The Roman bricks which I examined, were made of two dif ferent forts of clay mixed; when burnt, one appears red, and the other white: At the time of my viewing them they were exceeding hard and folid, and far fuperior to any thing of the kind now made with us. Perhaps they are little worse than when they were first laid down. These bricks were made without the afliftance or addition of fand, as is too much the practice at prefent here in Norfolk: For when fand enters the compofition in any conDfiderable proportion, it renders the brick friable, foft, and rotten, sub. ject to be broke or ground to pieces with the least motion or preffure. The ruins of two old towers ftill remain, one of which stood on the N. fide, and the other at the W. end; the last of which is at prefent the most confiderable of the two. They were E both built in a manner, perhaps, peculiar to the Romans at that time, and which it may not be improper to defcribe They began firit with a layer of bricks laid flat as in pavements; on that they placed a layer of clay and marle mixed together, and of the fame thickness as the bricks; then a layer of bricks, afterwards of clay and marle, then of bricks again, making in the whole three layers of bricks and two of clay : Over this were placed bricks and lime 29 inches, the outfide being faced with bricks cut in fquares (like the modern way of building in fome parts of Norfolk,) then bricks and clay again, ftratum fuper ftratum; as 5. G I took the exact dimenfions of feveral of these bricks, and found their length to be 17 inches, or a Roman foot and half; and their breadth 11 inches, or precifely a Roman foot: Which I think may serve as fome proof that the Roman meafures handed down to us by feveral authors are right, and may likewise inform us of the proportionable ftature of a man at that time. The thickness of these bricks is 1 inch. The great number of Roman medals that have been, and are fill found in and about this camp, are to me a matter of great wonder. One lady who lives near the place, has (I am credibly informed) picked up at least 100 with her own hands, and feveral are daily gathered up by boys, and fold to ftrangers who come to vifit the place. That 1751. More Extracts from the Phil. Tranfactions. A That thefe pieces have been used as money I think exceeding clear, from their different degrees of perfection, fome being worn almoft quite fmooth, others having imperfect bufts without letters, and others again having both the bufts and infcrip. tions fair and legible; which could not happen, I think, but from their different wear as money. But then how fuch quantities of them should become scattered, as if fown, in this and other Roman ftations, is a difficulty I must leave to thofe better B versed in these matters to refolve. 121 thereby become lefs, their periodical times will also be diminished. Thus in time the earth ought to come within the region of Venus, and in fine into that of Mercury, where it would neceffarily be burnt. Hence it is manifeft, that the fyftem of the planets cannot laft for ever in its (prefent) ftate. It also incontestably follows, that this fyftem must have had a beginning: For whoever denies it, mult grant me, that there was a time, when the earth was at the distance of Saturn, and even farther; and confequently, that no living creature could fubfift there. Nay, there muft have been a time, when the planets were nearer to some fixt ftar than to the fun; and in this cafe they could never come into the folar fyftem. This then is a proof, purely phyfical, that the world, in its prefent ftate, muft have had a beginning, and must have an end. In order to improve this notion, and to find with exactitude, how much the years become fhorter in each cenD tury, I am in hopes that a great number of older obfervations will afford me the neceffary fuccours. Part of a Letter from Leonard Euler, Prof. Math, at Berlin, and F. R. S. To the Rev. Mr. Cafpar Wetftein, Chaplain to his Royal Highness the Prince of Wales, concerning the C gradual Approach of the Earth to the Sun.After mentioning an Arabick MS. at Leyden, which contains a History of Aftronomical Obfervations, and wishing the fame were tranflated, he says: AM very impatient to see such a a F tions, that are not fo old as those recorded by Ptolemy. For having carefully examined the modern obfervations of the fun with those of fome centuries paft, altho' I have E not gone farther back than the 15th century, in which I have found Walther's observations made at Nuremberg; yet I have obferved, that the motion of the fun (or of the earth) is fenfibly accelerated fince that time; fo that the years are fhorter at present than formerly: The reafon of which is very natural; for if the earth, in its motion, fuffers fome little refiftance (which cannot be doubted, fince the space thro' which the planets move, is necessarily full of fome fubtile matter, G were it no other than that of light) the effect of this refiftance will gra dually bring the planets nearer and nearer the fun; and as their orbits March, 1751. An Account of an extraordinary Meteor feen in the county of Rutland, abich refembled a Water-Spout; by Tho. Barker, Efq; EPT. 15, 1749, a remarkable meteor was seen in Rutland, which I fufpect to have been of the fame kind as fpouts at fea. It was a calm, warm, and cloudy day, with fome gleams and fhowers; the barometer low and falling, and the wind S. and fmall. The fpout came between 5 and 6 in the evening; at 8 came a thunder-fhower, and storm of wind, which did mischief in fome places; and then it cleared up with a brifk N. W. Wind. The earliest account I have was from Seaton. A great fmoke rofe over or near Gretton, in Northamptonshire, with the likeness of fire, either one fingle flath, as the miller faid, |