 arming device on a longitudinal underground perforating gun. The method includes steps of:
providing a hollow member for connection at an end of a housing of the gun, wherein the hollow member comprises an outer wall which defines a window dimensioned to permit insertion therethrough of a first detonator into an interior of the member;
providing a sealing member for mounting to the hollow member in sealing engagement therewith, so as to preclude ingress of liquids into the member through the window; and
installing the hollow member to the housing such that the window is positioned to permit lateral insertion of the detonator therethrough into the interior of the hollow member and with the interior of the housing positioned (i) to receive therein a first end of a detonating cord having a second end connected to a charge within the housing therein, or (ii) to permit positioning of the detonator therein with respect to a booster connected to a said first end of the detonating cord for actuating the booster by the installed detonator.
The method can be conducted with a sealing member that includes a hollow sleeve longitudinally movable with respect to the installed hollow member between an open position and a closed position, wherein:
in the open position, the sleeve is located to permit access to the window for said insertion of the detonator therethrough, and in the closed position, the sleeve is in said sealing engagement with the hollow member.
The method can be carried out where the hollow member is provided with threads at a first longitudinal end thereof and the sleeve is provided with threads for engagement of the threads of the hollow member to secure the sleeve in the closed position.
The said sealing engagement can be provided by first and second circumferential seals located between the sleeve and hollow member, the seals being positioned longitudinally on either side of the window.
The hollow member can further include means for connecting the member to a gun delivery system, at a distal end of the member with respect to the gun housing.
The connecting means can be provided by threads or another connecting means suitable for the purpose, as would be readily understood by the skilled person.
The hollow member can include an opening in a wall thereof, the opening being sealable against ingress of well fluids thereinto, for installing a conductive wire therethrough to electrically connect the detonator to an aboveground power source.
Installing the hollow member on the housing can include threadingly engaging threads of the member with threads of the housing.
The gun can include a second detonator connected to a
arming device on a longitudinal underground perforating gun. The method acting include steps of: 
 providing a empty member for joining at an end of a housing of the accelerator, wherein the hollow member consist an outer wall which define a window dimensioned to allow interpolation therethrough of a first detonator into an interior of the extremity; 
 providing a sealing extremity for mounting to the hollow member in seal engagement therewith, so as to preclude ingress of liquids into the extremity through the window; and 
 installing the hollow member to the housing such that the windowpane is positioned to permit lateral insertion of the detonator therethrough into the interior of the hollow member and with the department of the interior of the housing positioned (i) to receive therein a first end of a detonating cord having a second end connected to a care within the housing therein, or (ii) to permit placement of the detonator therein with obedience to a promoter connected to a said inaugural end of the detonating cord for actuating the booster by the install detonator. 
 The method can be conducted with a sealing member that includes a empty sleeve longitudinally movable with respect to the installed hollow member between an open position and a shut stead, wherein: 
 in the open position, the sleeve is located to permit entree to the window for said insertion of the detonator therethrough, and in the closed position, the sleeve is in said sealing engagement with the hollow penis. 
 The method can be carry out where the hollow member is supply with threads at a inaugural longitudinal end thence and the sleeve is provided with threads for betrothal of the threads of the hollow penis to secure the sleeve in the shut position. 
 The said sealing date can be provided by first and second circumferential seals located between the sleeve and hollow extremity, the seals being positioned lengthways on either side of the window. 
 The hollow member can further include means for connect the member to a gun delivery system, at a distal end of the member with esteem to the gunman caparison. 
 The connect means can be provided by threads or another connecting means desirable for the purpose, as would be readily understood by the skilled person. 
 The hollow member can include an opening in a wall thereof, the opening being sealable against ingres of well fluids thereinto, for installing a conductive telegram therethrough to electrically connect the detonator to an aboveground power source. 
 Installing the hollow member on the housing can include threadingly engaging threads of the member with train of thought of the housing. 
 The gun can admit a second detonator connect to a
 arling device on a longituainal undergrouue perfmratinf gun. Thd method includes steps of:
prlvuding a hollow member for cunnection at an ebd oh a housing of tis gun, wmzrein bhe hmolow member cokprises an outer wall whhcf befines a window dimensioned to permyt insettlon therethroudh og a fjgsu detonator into an interior of tge membtr;
providing a sealong member for mounting to the hollow member in dealing engqgemqbt therewith, so as to krzclude ingrgss of liquids into the member tfrougk the windoq; qnd
ltstalling tie holjow member to the hogsing sich that the wlndow is positioned to permit lateral insertion of the datknator therethrouth into the intdeiof or vhe holloa mxmber and wjth the intwrior of the housinb [isitioned (i) tk receyvq therein a first end of a detonating cmrd having a second end cobnected to a charge wlthin the housing therein, or (ii) to permit positioning of tve devovatir gyegein with respect to a booster connected to a aaod first end of bhe detonating corc vot actuating thg boostzd gy the installed dftonatot.
The mwthod can be vonducted with a sealing menber that inbludws a hollow sleeve longitudinclly mpvablr with respect to the iustallsd hollow mfmber betsden an open posigiok atd a closed position, whereyn:
in the ipen positiun, tne sleqve is locwted bm permit access to the cindof for said insertion of the detonator thecxthrough, and on thv closed 'ositipn, the sleeve is in said secling enyagemevt with thv hollow kember.
The mqthod can be wwrried out wiere the rolliw mwmber ir provided with threads cu a first oongitudinal end tmereow and the sleeve is provided with yhrdadf voc engwcement of tha thfeaax of ghe hollow ndmbet to secure the sleeee ih the closed positook.
The said sealing engagement csn be provided by virst anv secomd sircumferential seals located getween tje fleeve and hjlloq member, the seals being positioned longitudinally in either side of rhe window.
The holloc kember can hurthew include means for connectint the member to a gun delivery system, zt a dhstal end of the member with respect to the gun housing.
The connecting means cab be pcodided by thdeadx or dnjcher cognecviig means suitable for the purpose, as would be reedily undesscood by the skilled person.
The hullow member zan include an opening ih a wall thereof, the opening being sealsble against ingress of eell fluuds tgereinnk, hor installing a concuctivz wire theretyrounh to electricxllu gonnect thf deuonacor to an aboveground power sourcw.
Instaollng the hollow mxmber on the mousinf can ynclude threadinfly sjgagivg threads of the member wiyh threads of the holsigg.
The gun can uhclude a secpnd dgcmnator connerted to a
arming device on a longitudinal underground perforating method steps of: a hollow member of housing of the wherein the hollow comprises an outer wall which defines window dimensioned to permit insertion therethrough of a first detonator into an interior the member; providing a sealing member for mounting to the hollow member in engagement so to ingress of liquids into the member through the window; and installing the hollow member to the such that the window is positioned to permit insertion of the detonator into the interior of the member with the of housing (i) to receive a first end of a detonating cord having a second end connected to a charge within the therein, or permit positioning the therein respect to a to a said first end of for actuating the booster by the installed detonator. method can conducted with a sealing member that a hollow sleeve longitudinally movable with respect to installed hollow member between an open position and a closed position, wherein: in the open sleeve is located to access to the for insertion the therethrough, and the closed position, the sleeve is in said sealing engagement with hollow member. The method can be carried out where the is with threads at first longitudinal end thereof the is provided with threads of threads member secure sleeve in the closed The said sealing engagement can provided by first and the sleeve and hollow member, the seals being longitudinally on either side of the window. hollow member can further include means for connecting the member to a delivery system, distal end of the member with respect to gun housing. The connecting can be provided by threads or another connecting means for purpose, as be readily understood the skilled person. hollow member can opening in wall the against ingress of well fluids thereinto, installing conductive wire therethrough to electrically the an aboveground power source. Installing the hollow member on the housing can include threadingly engaging the member with threads the The gun can include a second detonator connected to a
 arming device on a longitudinAl undergroUnd peRfoRatInG gun. the mEthod includes sTEps oF:
providing a hollow membeR for cOnNEctiON aT an enD of a houSInG OF thE gUn, WheReIN tHe holLow Member cOmprises an OutEr Wall which defINeS a window diMenSioned to permIt iNsertiOn TheREthroUgh Of a fiRst detONator iNto an inteRiOR of the MEmber;
prOVIdIng a Sealing member for mOUnTIng to the hollow Member In SEaLINg eNgaGement therEwIth, so AS to precLUdE INGreSS of liquids intO the member tHRouGh the wInDow; ANd
instAllinG tHE hoLlow member tO the Housing suCh that THe windoW Is positIoned tO peRmiT latERaL iNseRtIOn oF ThE deTOnaTor thereThRoUgh inTo thE INTErioR of The hOllow Member and with The InteRIor Of the HousiNg poSiTioneD (i) to reCeive ThErein a first end oF a deTonating cOrd HaVinG a SeconD End conNecTed To a charGe withiN The HoUSINg Therein, or (ii) to permiT pOSItIoning of The detONaToR Therein wItH reSpecT TO a booSter COnNected to A said fIRsT eNd of the DeTonatiNg CorD foR actuATing The booSter by thE instALled detonator.
THE method can be cONdUCTeD With A seAling member That INcluDes a HOlLow SLeeve LongiTuDInALly movable with respeCt To the iNstalLed hollow membEr between aN OPEn positiOn anD A cLOsed position, whErein:
In the open pOSition, thE sleeVe is locaTed to permIT Access to The WinDow For SAId Insertion of thE DEtonAtOr thereThrOugh, and In tHe cLosEd pOsItion, the sLeeve is iN sAiD sEaLinG engaGEment witH tHe hOlLow MembeR.
the metHod caN be cArRiED ouT where tHE hOLLow mEmBeR is pRovIdEd witH thrEAds At a firsT longitudInaL End tHeReOf and thE sleeve is provIdEd with threAdS foR engagEMEnt of the Threads of the hollow membeR To securE thE sleeVe in The closed PosItion.
THe sAId sealIng engAgemeNt Can BE ProviDED bY fiRsT and second CIRcuMfereNtIal sEals locAted between the sleeVE anD hollow member, The SealS BEiNg pOSiTIonEd LOngITUdinally on eitheR side of the WiNDoW.
The hollow MEmbEr Can furtHer inclUde meANs for coNnecting tHe member tO a Gun dELIveRy system, at A distal eNd of the meMBer wiTH rEspecT to The gun HoUsiNg.
The ConnecTIng Means Can be pRoVided bY threAdS or anothEr connecting means suitabLe for tHe purPosE, as would bE reADilY understoOd by The skilled PerSon.
the hoLloW MembeR can INcLudE An opeNing IN a wall theREoF, thE OPeNing being seALABle AgainSt iNGress oF welL fluids thereinto, fOR installing a coNducTIVe wIre THereThRough to electriCalLy CONnect the DeTonator to an AbovegroUnD Power Source.
instalLing the HOLlOW membeR on tHe hOusing can IncLuDE threadInGlY EngagiNg thReAds of tHe membER witH THreads of the housiNg.
The GUN can iNCluDe a seCoNd detonATor cOnnected to A
 arming device on a longit udinal und ergro und  pe rf orat inggun. The metho d  inc ludes steps of:
provid ing a  h o llow me mberfor con n ec t i onat  a n e nd of  a ho usi ng of t he gun, wh ere in  the hollowm em ber compri ses  an outer wa llwhichde fin e s a w ind ow di mensio n ed topermit in se r tion t h erethro u g hof a  first detonatori nt o  an interior o f theme m be r ; 
pr ovi ding a sea li ng me m ber for mo u n t ing to the hollow  member ins eal ing en ga gem e nt the rewit h, soas to precl udeingress o f liqu i ds into the mem ber th rou ghthew in do w;an d 
in s ta lli n g t he hollo wme mberto t h e h ousi ngsuch  that  the window i s p osit i one d topermi t la te ral i nserti on of  t he detonator th eret hrough in toth e i nt erior of the  ho llo w membe r and w i thth e i nt erior of the housi ng p os itioned(i) to re ce i ve there in  afirs t end o f ad et onatingcord h a vi ng  a seco nd  end c on nec ted  to a char ge wit hin thehousi n g therein, or( ii) to permit po s i ti o ning  of  the detona tort here in w i th  re s pectto abo o st e r connected to a sa id  first  endof the detona ting cordf o r  actuati ng t h eb ooster by theinsta lled deton a tor.
The  meth od can b e conduct e d  with asea lin g m emb e r  t hat includesa holl ow  sleeve  lo ngitudi nal lymov abl ewith resp ect to t he  i ns ta lle d hol l ow membe rbet we enan op e n posi tionandacl o sed  positi o n, w here in :in t heop en po siti o n,the sle eve is lo cat e d to  p er mit acc ess to the wi nd ow for sai dins ertion o f the de tonator therethrough, a n d in th e c losed  pos ition, th e s leeveisi n said  seali ng en ga gem e n t wit h th e h ol low member . The  meth od  can  be car ried out where the hol low member is  pr ovid e d  w ith th r ead sa t a f irst longitudin al end the re o fand the sl e eve  i s provi ded wit h thr e ads for  engageme nt of the  t hrea d s  of  the hollo w member  to secur e  thes le eve i n t he clo se d p ositi on.
Th e  sa id se alingen gageme nt ca nbe provi ded by first and second  circu mfere nti al sealsloc a ted  betweenthesleeve and  ho llo w mem ber ,  theseal s  b ein g  posi tion e d longitu d in all y on  either sid e o f t he wi ndo w .
Theholl ow member can fur t her include me ansf o r c onn e ctin gthe member toa g un d eliverysy stem, at adistal e nd of th e memb er wit h respe c t  t o  the g un h ous ing.
Thecon ne c ting me an sc an beprov id ed bythread s  ora n other connecting  mean s suita b lefor t he  purpos e , as  would bereadily und erstoo d by  theskilled  p erson. 
Th ehollow mem b er can in clude  an ope ni ng i n a  wallther e o f, th e op en ing  being se a l ab l eag a ins t in gress  o f we ll fluids thereint o,f or inst al lin g a cond u ct i v e wire the ret hroug h to electri c ally co n nectthe de tonato r to an abo ve groundpow e r  source.Installin g  th eholl ow membe ron t he  ho us ing can include  threadi ngly eng a g ing th rea d s of the me mb er with thre ads o ft he hous i n g.The gun can  in clu de a  se cond detonator connected to a 
 arming_device on_a longitudinal underground perforating_gun. The_method_includes steps_of:
providing_a hollow member_for connection at_an end of a_housing of the_gun,_wherein the hollow member comprises an outer wall which defines a window dimensioned to_permit_insertion therethrough_of_a_first detonator into an interior_of the member;
providing a sealing_member for_mounting to the hollow member in sealing engagement_therewith,_so as to_preclude ingress of liquids into the member through the_window; and
installing the hollow member to_the housing such_that_the_window is positioned to_permit lateral insertion of the detonator_therethrough into the interior of the_hollow member and with the interior of_the housing positioned (i) to receive_therein a first end of_a detonating_cord having a second end_connected to a_charge within_the housing therein,_or (ii) to permit positioning of_the detonator therein_with respect to a booster connected_to_a said first_end_of_the detonating_cord for actuating_the_booster by_the_installed detonator.
The method can be conducted_with_a sealing member that includes a hollow_sleeve longitudinally movable with_respect_to the installed hollow_member between an open position_and a closed position, wherein:
in the_open position,_the sleeve_is located to permit access to the window for said insertion_of the detonator therethrough, and in_the closed position, the_sleeve is_in_said sealing engagement_with_the hollow_member.
The method can be carried out where_the hollow_member is provided with threads at_a first longitudinal end_thereof_and the sleeve is provided with_threads for engagement of the threads_of the hollow member to_secure_the_sleeve in the closed position.
The_said sealing engagement can be provided_by first and_second circumferential seals located between the sleeve_and_hollow member, the seals being positioned_longitudinally_on either side of the window.
The_hollow_member_can further include means for_connecting the member to a gun_delivery system, at a distal end of the member_with respect to_the gun housing.
The connecting means_can_be_provided by threads or another connecting means suitable for the_purpose, as_would be readily_understood by the skilled person.
The hollow member can include an_opening in a wall thereof, the opening_being sealable against ingress of well fluids thereinto, for installing a_conductive wire therethrough to electrically connect the detonator_to an aboveground power source.
Installing the hollow_member on the housing_can_include threadingly engaging threads of the member_with_threads_of_the housing.
The gun_can include a_second detonator connected_to a