r;i I rS'-.ivr. 



PILGRIM. 



he* **mimed anything like a scientific character, or hu admitted the 

 application of any mchniol power other than mere brut* strength. 



The ptle-engiiw* wliich are (till tud in ouuntriei behind the (pint 

 of the age in the development of the mechanical arU, such a* Holland, 

 Germany, Spain, or Iuly, ore the old faahined ringing enginr, in 

 lu.-li a monkey, or a Urge hammer, ii railed by meant of a pulley 

 and a rope, the latter being connected with a grrat number of cords, 

 which are pulled in unUon by an equal number of men. The weight 

 of the monkey of these machine* i* usually about 10 or 13 cwt, and 

 the fall u only from 4 feet to 4 feet 8 inohm ; and in practice it U 

 found that the dynamical foroe, thus brought to bear upon the pile*, 

 u not sufficient to drive them through grounds of any notable degree 

 of resistance ; the ringing engines, moreover, require so much space, 

 and so great a number of men, as to render their use extremely incon- 

 venient when numerous piles have to be driven in a small area. 



In England anil in France the pile-engines generally used consist of 

 a vertical frame of about 24 feet, or at times 80 feet, in height, bearing 

 at the top a pulley, over which passe* a chain starting from a crab 

 fixed pn the ground, and able to reach a monkey resting, when the 

 machinery is in repose, on the pile head. When the pile is being 

 driven the monkey is raised until some fixed pins open the clutch 

 which supports the monkey, and the latter then falls on the pile head ; 

 the usual weight of the monkey is from 12 to 18 cwt, and the fall 

 varies from 12 to 18 feet, according to the resistance the pile meets 

 with in its descent ; occasionally the, fall may be extended to 26 feet, 

 and the crabs are often worked by steam, when the number of piles to 

 be driven within a given area is considerable. The principal objection 

 to the use of these engine* consists in the danger which must exist of 

 tlii'ir splitting the piles, either by turning the shoe, or by the develop- 

 ment of cross fissures, from the enormous force of the blow produced 

 by a great weight falling from a great height ; but at the same time 

 the rate of advance they produce is very rapid, and they are econo- 

 mically worked. 



The various systems for sinking piles by pneumatic pressure have 

 not hitherto succeeded well, when applied to piles of the dimensions 

 ordinarily used, although their results have been satisfactory when 

 large cylinders have been used. At the present day these systems 

 have been almost entirely abandoned ; and when it is necessary to 

 sink even large hollow cylinders, to a very great depth through light 

 soil, the use of caissons working with compressed air, in the same 

 manner as was done at the Rochester or the Saltash bridges, has been 

 substituted for the costly and partially inefficient methods of pile 

 driving by pneumatic pressure. In fact, the latter system consists in 

 creating a vacuum beneath a surface exposed to the air, and the 

 it of the atmosphere in excess of the weight of the enclosed air is 

 supposed to cause the pile to descend ; but it frequently happens, that 

 in proportion as the internal air is withdrawn, so does the moveable 

 ground beneath it follow into the open space ; and by thus compressing 

 the air in the interior it annihilates the difference between the two 

 pressures. Whereas, when the compressed air is used, a fresh quantity 

 u pumped into the interior of the cylinders until it attains a pressure 

 of about 60 Ibs. on the square inch, which is sufficient to prevent any 

 running sand, or semifluid mud, from rising under ordinary hydrostatic 

 I pressure at least. But it must be repeated that either of these systems 

 i adapted to sinking caissons rather than piles, although they might 

 originally have been applied to the Utter. 



The Mitchell's Krtio-pilei are so called, because they are made with 

 the worm of a screw at their extremity, and they are driven by turning 

 them in the ground in precisely the same manner as an ordinary screw 

 is driven into wood. It must, however, be evident, that piles so 

 driven do not compress the ground in any appreciable manner ; and 

 that they do not furnish any direct evidence of the amount of 

 resistance they offer to vertical compression. The Mitchell's piles are 

 admirably adapted to resist efforts of tension, as in the case of the dead 

 works of a floating buoy, or of a hauling lump, or mooring block ; 

 because the whole prism of earth around the screw must be torn out 

 before they can move, and the same condition renders them equally 

 'fitted for the piles of piers driven into tolerably firm and even soils, 

 which pen are expoaed to cross seas, but are not exposed to heavy 

 vertical weight*. The easy descent of the Mitchell's piles, and the 

 abeenoe of vibration whilst they are descending, may, in many practical 

 instances, constitute a great recommendation for them. 



The most striking illustration of the adaptation of machinery to 

 pile driving, u perhaps the application of the Nasmyth's steam hammer 

 to this purpose. In this case the steam is admitted into the bottom 

 of a cylinder bearing a piston-rod connected directly with the monkey, 

 so as to raise it vertically until the piston reaches the head of the 

 xtroke ; the (team then escapes, and the piston falls. The weight of 

 the monkey in these engines need only be limited by the capacity of 

 the cylinder, or by the elasticity of the steam ; and it is in practice 

 made to range between 32 and 46 cwt. ; but the height of the fall u 

 limited by the length of the stroke, and it rarely exceeds 2 feet 6 inches. 



the ordinary pile engine*, the number of blows does not exceed 35 

 or 40 per hour ; but with the Nasmyth's hammer it U easy to increase 

 tfcat number to between 60 or 60 per minute. It follows from the 

 yi.amioal condition* of this engine, that in ordinary cUys, sands, or 

 alluvtai Uepuaiu, where the resistance to the descent of the piles is not 

 very great, and i* tolerably uniform, that the Nasmyth's pile-engine 



drive* piles with a rapidity for greater than any other machine hitherto 

 applied to such a purpose ; but when the resistance becomes cor 

 able, the piles are very much ex|M*ed to be beaten up, to be set on fire, 

 or to be broken by the frequent blow* ; or if those result* should not 

 occur, they may be set into such a state of vibration as to oppose a 

 seriou* resistance to their descent The writer of this article ha* 

 actually seen 8880 blows struck in 1J hour upon a 14 square ] 

 a monkey of 42 cwt. falling 2 feet 6 inches, without causing it to 

 advance more than S inches ; but the heed of the pile was literally 

 beaten up into a sponge : an ordinary pile-engine with a monkey of 

 16 cwt. falling 18 feet, would, in six hours, have produced a greater 

 dynamical effect under far more advantageous conditions. The use of 

 tho Nasmyth's steam pile-driver should therefore be limited to the 

 class of soil* above-named; but in driving through hard gnu 

 tufaceou* limestone, the monkeys with large falls and slower 

 should be used : in fact, the mechanical effect produced by a w i-ijlit 

 falling on the head of a pile is such that the descent of tl.. ]<il.- is 

 proportional to the fall of the monkey ; and it is admitted that 

 economically there is an advantage in the adoption of heavy monkeys 

 falling through height* ranging between 12 and 20 feet It has been 

 shown, by direct experiment, that the descent of a pile is proportional 

 to the mass of the monkey, added to that of the pile, multiplied by 

 the square of the common velocity of those two bodies after tin- 

 For if the mass of the monkey be represented by m, and that of the 

 pile by m', the common velocity of the monkey and of the pile by H, 

 and the velocity of the monkey before the shock by V, the descent may 

 be derived from the following formula : 



(* + ') '=(+*') _*_- !ZL 

 (m + m') 1 (m + m') 



but as in this case V i -^yh, in which g= the accelerating force of 

 gravity (32J feet in London), and h = the fall of the monkey, the 



descent of the pile U proportional to 22^ = ^5*. 



m + m 1-t-m 



The nature of the soil to be traversed, and the number of piles to be 

 driven in a given time, must be the determining motives for tin 

 tion of the pile-driving machinery to be adopted. For camp-sheeting 

 tho ringing engine will suffice ; tho Nasmyth's hammer is admirably 

 adapted to soft, equable, soils ; but the ordinary pile-engine worked by 

 crabs is the best fitted for hard irregular soils. 



PILES. [VEINS, DISEASES OF THE.] 



PILGRIM is the name given to a person who travels for the purpose 

 of visiting the shrines or tombs of holy men, or places which from any 

 cause have come to be regarded as sacred ; and the act itself it 

 called Pilgrimage. The words pilgrim in English, pilr/er in German, 

 ptllnjritio in Italian, pfltrin in French, are all corruptions of the Latin 

 " peregrinus," which means a stranger or foreigner. Pilgrimages to 

 Jerusalem, Bethlehem, and other places which were the scenes of tho 

 Saviour's life and death, and which are included in the general name 

 of the " Holy Land," began at an early period, probably about the 

 time of Constantine. We are told by Eusebius and others that 

 Helena, Constantino's mother, proceeded on a pilgrimage to Palestine, 

 and built the church of the Holy Sepulchre. The practice became 

 common about the end of the 4th century, and we find it noticed as 

 such by the fathers of tho church, Jerome, Augustine, and other*. 

 Gregory of Nyssa, in one of his epistles, reproves the indiscriminate 

 custom of pilgrimages, especially by women, who, he observes, were 

 particularly exposed during a long and toilsome journey through 

 countries like Syria, notorious for licentiousness of manners. His 

 opinions concerning pilgrimages are in accordance with those expressed 

 by other fathers of the church. St. Augustine, St. Chrysostom, and 

 St. Jerome, all agree as to the uselessness of such pilgrimages. 



In tho course of time, however, the practice of pilgrimage increased, 

 and extended to other places besides Palestine. People resorted to the 

 shrines of St Peter and St. Paul at Rome, to that of St In 

 CompostelU in Spain, of St Gregory of Tours in France, to the 

 monastery of Einsiedlen in Switzerland, to our Lady of Loreto in 

 Italy, to the tomb of Thomas a Becket at Canterbury, and to many 

 other place*. 



The pilgrim's garb was a gray or brown gown, a broad-brimmed hat 

 adorned with a palm leaf if going to the Holy Land, or a scallop-shell 

 if going to other places, with a long staff round at one end and pointed 

 at the other ; and his pouch was a hollowed gourd. 



In the west, the celebration of the Jubilee perpetuated the custom 

 of pilgrimages to Borne. The institution of the Roman Jubilee is due 

 to Boniface VIII. At the beginning of the year 1300, a report was 

 spread at Rome that all those who should visit the church of St. 

 Peter that year would obtain a plenary indulgence, and that every 

 centenary year enjoyed the same privilege. Pope Boniface *earrli< . I 

 the ancient records for the grounds of this report, and he interrogated 

 a man 107 yean old, who told him that in the year 1200 his fatlirr. a 

 labouring man, had gone to Rome to get the indulgence, and had 

 advised him, if he should live to the next centenary, to follow hi* 

 example, Some other old men in France and Italy confirmed tlii* 

 tradition. After consulting the College of Cardinals. Boniface ix 

 bull, stating that "as according to the faithful report of the eMi T* 

 great indulgence* are granted to those who visit the church of the 



